Patient interface and aspects thereof

ABSTRACT

A patient interface has a single loop headstrap and a mask for covering at least the nostrils of the user. The single loop headstrap extends from the mask at either end. A short length of supple conduit is coupled to the mask by a swivel or ball joint to allow rotation of the conduit relative to the mask through different angles and orientations.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference and made a part of thepresent disclosure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to interfaces for providing asupply of pressurised gas to a recipient via the nasal passages. Thepresent invention also generally relates to devices that also supply gasto the oral passages, for example, by incorporation into a broader fullface mask.

2. Description of the Related Art

The prior art includes a wide variety of interfaces for supplying gasesto a recipient. For example, the prior art includes a nasal mask thatcan be used for supplying gases to a recipient. The nasal mask includesa perimeter seal that seals across, down each cheek alongside the noseand along the surface of the upper lip. The entire enclosed space ispressurised and the recipient may inhale the pressurised gas from theenclosed space. An example is the Flexifit 405™ nasal mask sold byFisher & Paykel Healthcare.

The prior art also includes a full face mask. The full face maskincludes a perimeter seal that extends across the bridge of the nosedownward along each cheek beside the nose to the jaw and along the jawbelow the lower lip. The perimeter thereby encloses both the nose andmouth. The entire space within the mask frame is pressurised. Therecipient may breathe the pressurised gas from the space through eitherthe nose or mouth. An example is the Flexifit 431™ interface sold byFisher & Paykel Healthcare.

The prior art includes an oral interface including an oral appliancethat fits within the user's mouth. An example is the Fisher & PaykelHealthcare Oracle interface.

The prior art includes a nasal pillows interface in which headgearretains a soft plenum in the vicinity of the user's nose. A pair offlexible protrusions engage against the nares of the recipient.Typically, the protrusions are able to axially compress and have alateral freedom of movement relative to the supporting cushion. Anexample is the ResMed Swift™ nasal pillows interface.

The prior art includes a nasal cannula interface. The nasal canalinterface includes a plenum portion that rests against the upper lip ofthe user and a pair of prongs. Each prong extends into the nostril ofthe user. An example is the Nasal-Aire™ interface made by Innomed.

Interfaces such as these are frequently used for delivering pressurisedgases to a person being treated for obstructive sleep apnea (OSA) orother sleep disorders. These users typically wear the interface in ahome sleeping environment. Comfort and effective sealing even underconditions of patient movement are major considerations.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an interface which willat least provide the industry and users with useful choice.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface comprising a supple envelope,bag or balloon, with an air supply aperture and a pair of protrudingnostril locators protruding from the envelope, each nasal locatorincluding an outlet aperture, the envelope, bag or balloon inflatingunder internal pressure from a pressurised gases supply and when pressedagainst the face of a user, creating a seal with the nose or face of theuser in addition to any seal provided by the nasal locators.

According to a further aspect the envelope has at least two integralconnectors to attach a head strap to the envelope.

According to a further aspect the interface includes a frame having agases inlet for connection with a gases supply conduit and a gasesoutlet including a protruding lip, where the gases supply aperture ofthe envelope is engaged or engagable over the protruding lip of theframe.

According to a further aspect the frame has at least two integralconnectors to attach a head strap to the frame.

According to a further aspect the frame includes a strap to stabilisethe envelope, the strap extending above the frame.

According to a further aspect the strap is integrally formed with theframe.

According to a further aspect the strap is separate to the frame yetfastened to said frame.

According to a further aspect the envelope includes an elongate stripintegrally formed in the envelope to stabilise the envelope, the stripextending in an arc above the frame.

According to a further aspect the envelope, when inflated withoutstretch, will not pass through a circular aperture of 40 mm diameterwithout contact.

According to a further aspect the envelope collapses when not inflated.

According to a further aspect the envelope or the body of the envelope,in use, forms a substantially continuous seal against the user's noseand face that surrounds the nostril locators.

According to a further aspect the envelope wraps completely about theuser's nose.

According to a further aspect the envelope has side portions that extendcompletely about the sides of the user's nose and at least partiallyover the user's cheeks.

According to a further aspect the envelope has a cut out in the nasalbridge region of the user.

According to a further aspect wherein, in use, the side wall of theenvelope rolls to accommodate movement of the mask frame relative to thenose, wherein rolls means that the portion of the envelope adjacent tothe frame reduces at one side and extends at the other, and thecorresponding portions adjacent the face extend at one side and reduceat the other.

According to a further aspect the envelope allows for this movement inany direction relative to the nose.

According to a further aspect the envelope allows for a roll of at least10 mm without exposing the nostril locators.

According to a further aspect substantially the entire envelope, exceptfor a region immediately adjacent and including the nostril locators andimmediately adjacent and including the inlet opening, is supple, and theregion immediately adjacent and including the area immediately adjacentthe inlet opening has any suitable stiffness.

According to a further aspect the region immediately adjacent the inletopening is stiffer than the rest of the envelope.

According to a further aspect the region immediately adjacent thenostril locators is stiffer than the rest of the envelope.

According to a further aspect a connector is engaged with or formed inthe interface frame.

According to a further aspect the interface includes a short length ofsupple breathing conduit that is connectable to the frame.

According to a further aspect the interface includes a including a shortlength of breathable conduit that is connectable to the frame.

According to a further aspect the interface includes a lanyard or tetherconnected to a length of breathing conduit connected to the frame.

According to a further aspect the lanyard or tether is connected to theconduit at a location between 10 cm and 50 cm from the frame.

According to a further aspect the interface includes a frame supportingthe envelope, the frame including at least one soft or flexible portionat the perimeter.

According to a further aspect the frame includes at least a pair ofextended support members at the perimeter, the support members locatedeither side of the frame such that they may, but do not necessarily,contact portions of the face of the user in use.

According to a further aspect the interface includes at least one strapextending from one side portion of the frame to the other side portionof the frame, the strap being sufficient to pass around the back of thehead of the user.

According to a further aspect the strap is adjustable in length.

According to a further aspect each end of the strap is bifurcated andthe two limbs of the bifurcated end connect to the side portion of theframe at spaced apart locations.

According to a further aspect the interface includes a bias flow outletin one or more of the envelope, a frame or connector.

According to a further aspect the envelope is inflated and holds itsshape against the force of gravity with an elevated internal pressureequivalent to 3 cm H₂O.

Certain features, aspects and advantages of an embodiment of theinvention comprises an interface that includes an inflatable envelope(that could also be referred to as a bag or balloon) having a supplewall structure. The inflatable envelope has a pair of locatingprotrusions that engage in the nostrils of the user. The locatingprotrusions supply gases flow to the user from inside the envelope. Theenvelope is so supple, and of sufficient dimension and shape, that whenthe inflated envelope is pressed against the face of a user, with thelocating protrusions engaged in the nostrils of the user, the envelopecontacts the surfaces of the user's face (the nose, the upper lip andthe cheeks) and provides a seal.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface comprising: a single loopheadstrap, a mask for covering at least the nostrils of the user, thesingle loop headstrap extending from the mask at either end, a swivel orball joint at the mask to couple a supply conduit to the mask in use toallow rotation of the supply conduit through different angles andorientations relative to the mask.

According to a further aspect, the mask includes an inflatable seal withan air supply aperture and a pair of protruding nostril locatorsprotruding from the seal, each nasal locator including an outletaperture.

According to a further aspect, the seal inflates under internal pressurefrom a pressurised gases supply and when pressed against the face of auser, creating a seal with the nose or face of the user in addition toany seal provided by the nasal locators.

According to a further aspect, the interface includes a frame having agases inlet for connection with a gases supply conduit, and a gasesoutlet including a protruding lip, and the gases supply aperture of theseal is engaged or engagable over the protruding lip of the frame.

According to a further aspect, the seal, in use, forms a substantiallycontinuous seal against the user's nose and face that surrounds thenostril locators.

According to a further aspect, except for a region immediately adjacentand including the nostril locators and immediately adjacent andincluding the air supply aperture, the seal is supple, and the regionimmediately adjacent and including, the inlet opening and has anysuitable stiffness.

According to a further aspect, the patient interface includes at least apair of extended support members at the perimeter of the mask, thesupport members located either side of the mask such that they may, butdo not necessarily, contact portions of the face of the user in use.

According to a further aspect, the strap extends from one side portionof the frame to the other side portion of the frame, the strap beingsufficient to pass around the back of the head of the user.

According to a further aspect, the patient interface includes a shortlength of supple conduit connected to the swivel or ball joint.

According to a further aspect, the patient interface includes alaterally extended support that can press on a lower facial portion ofthe user outside the periphery of the seal.

According to a further aspect, the laterally extended support can presson the lower cheek portion of the user.

According to a further aspect, the laterally extended support may onlyoccasionally contact the face of the user in use.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface including a mask including sealmeans for sealing with the face of a user and frame means for supportingthe seal, and means for securing the mask to the head of a user.

According to a further aspect, the patient interface includes a conduitfor delivering gases to the mask, and means for supporting the weight ofthe conduit from substantially affecting the mask in use.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface comprising: a mask for coveringat least the nostrils of the user, and including a seal body and a frameconnected with the seal and a laterally extended support that can presson a lower facial portion of the user outside the periphery of the seal.

According to a further aspect, the mask includes an inflatable seal withan air supply aperture and a pair of protruding nostril locatorsprotruding from the seal, each nasal locator including an outletaperture.

According to a further aspect, the seal inflates under internal pressurefrom a pressurised gases supply and when pressed against the face of auser, creating a seal with the nose or face of the user in addition toany seal provided by the nasal locators.

According to a further aspect, in use, the side wall of the enveloperolls to accommodate movement of the mask frame relative to the nose,wherein rolls means that the portion of the envelope adjacent to theframe reduces at one side and extends at the other, and thecorresponding portions adjacent the face extend at one side and reduceat the other.

According to a further aspect, the frame includes at least a pair ofextended support members at the perimeter, the support members locatedeither side of the frame such that they may, but do not necessarily,contact portions of the face of the use in use.

According to a further aspect, the patient interface includes a singleloop strap extending from one side portion of the frame to the otherside portion of the frame, the strap being sufficient to pass around theback of the head of the user.

According to a further aspect, the laterally extended support can presson the lower cheek portion of the user.

According to a further aspect, the laterally extended support may onlyoccasionally contact the face of the user in use.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface comprising: a nasal sealincluding a face contacting side, the nasal seal being formed of a softflexible material, and including a central portion to extend across thebase of the nose, and a side portion extending from each end of thecentral portion, each side portion extending across the a side of thenose, a face contacting side of the seal being supple to conform underinternal pressure to the surfaces of the nose of a wearer, including, atthe side portions of the seal, to outside surfaces of the sides of thenose, an exterior side including regions much stiffer than the suppleinterior side, the regions extending into the side portions of the seal.

According to a further aspect, wherein the side portions of the seal aresubstantially parallel to each other and substantially normal to thecentral portion of the seal.

According to a further aspect, the outer walls of the side portions ofthe seal are aligned to have an angle between their orientations between0 degrees and 30 degrees.

According to a further aspect, the seal includes a pair of nasallocators on the face contacting side, and the seal is stiffer in theregion immediately adjacent and including the nasal locators than in aregion surrounding this region, on the face contacting side of the seal.

According to a further aspect, a peripheral portion of the seal, joiningthe face contacting side to the exterior side is supple and allows theinterior side of the seal to displace relative to the exterior side.

According to a further aspect, the exterior side of the central portionof the seal includes an aperture for passing gases to and from theinterior of the seal.

According to a further aspect, the supple portions of the seal comprisea silicone material with a thickness between 0.05 mm and 0.5 mm.

According to a further aspect, the supple portions of the seal comprisean elastomer with a thickness between 0.1 mm and 0.2 mm.

According to a further aspect, the stiff portions of the seal comprise asilicone material with a thickness between 2 mm and 5 mm.

According to a further aspect, the stiff portions of the seal comprisean elastomer with a thickness between 2 mm and 3 mm.

According to a further aspect, the region immediately adjacent andincluding the nasal locators comprises a silicone material with athickness between 0.5 mm and 2 mm.

According to a further aspect, the seal has an overall width fromoutside surface of one side portion to outside surface of the other sideportion of between 30 mm and 60 mm.

According to a further aspect, the seal has an overall depth, from theouter surface of the central portion to a line joining the extreme endsof each side portion, between 40 mm and 65 mm.

According to a further aspect, the patient interface includes a bodyassembled to the nasal seal, the body being formed of a material morerigid than the nasal seal, and together with the nasal seal forming anenclosure having an inlet opening and a patient outlet opening, with aswivelling elbow connected to the inlet opening.

According to a further aspect, the connection of the swivel elbow to thebody provides for rotation of the swivel elbow relative to the body andpivoting of the swivel elbow relative to the body about at least atransverse axis.

According to a further aspect, the connection comprises a ball joint.

According to a further aspect, the elbow includes a first end and asecond end and a flow path between the first end and the second end, theflow path aligned in the first direction at the first end and the seconddirection at the second end, and the first direction and the seconddirection including an angle of between 120° and 180°,

According to a further aspect, the angle is between 120° and 150°.

According to a further aspect, the angle is between 130° and 140°.

According to a further aspect, the elbow includes a gas washout vent.

According to a further aspect, the gas washout vent is aligned with agas flow path into the elbow from the nasal seal and body assembly.

According to a further aspect, the gas washout vent comprises aplurality of holes through a wall of the elbow.

According to a further aspect, the patient interface includes a bodyassembled to the seal, and a strap extending from the assembled body andnasal seal in a loop, the strap departing a first portion of theassembled body and nasal seal at one end and a second portion of theassembled body and nasal seal at its other end.

According to a further aspect, the strap comprises a single undividedband along the length of the strap that engages the head of the wearer.

According to a further aspect, the strap engages the body at either end.

According to a further aspect, the body is formed from a rigid material,the strap is relatively flexible compared to the body and includes asoft portion, a portion of the strap that engages the body formed of amaterial more flexible than the material of the boy and less flexiblethan the material of the strap such that, when engaged to the body, thesoft portion forms a soft extension of the body.

According to a further aspect, the soft portion extends 5 mm to 60 mmalong the strap.

According to a further aspect, the strap engages the body with areleasable connector at either end.

According to a further aspect, the strap includes a soft cover portionextending from the releasable connector for a distance of 5 mm to 60 mmalong the strap, the soft cover portion being formed of a materialsofter than the body.

According to a further aspect, the band is narrow, preferably less than10 mm wide.

According to a further aspect, the band is less than 6 mm wide.

According to a further aspect, the band has a stiffness less than 2 Nper 100 mm extension from a relaxed condition.

According to a further aspect, the band is formed from a knitted orbraided yarn incorporating filaments of a material with high elasticityand filaments of material of much higher stiffness.

According to a further aspect, the strap includes soft end portions thatare more rigid than the strap between the end portions, but softer thanthe body, the soft end portions also acting as soft extension portionsof the body.

According to a further aspect, the patient interface includes a tubedepending from the seal and body, and a tube support, connected to thetube and connectable to the neck or clothing of a patient.

According to a further aspect, the tube support includes a collarfastenable about the neck of a wearer.

According to a further aspect, the collar has a first end portion and asecond end portion, the first end portion and the second end portioninclude a fastening arrangement allowing the end portions to be fastenedwith a selected amount of overlap.

According to a further aspect, the collar includes a third end portionand a fourth end portion and a connector connecting the third endportion to the fourth end portion.

According to a further aspect, the connector is configured to releasethe third end portion from the fourth end portion upon application oftension across the connector greater than a release tension, wherein therelease tension is less than 10 N.

According to a further aspect, the collar is between 30 mm and 60 mmwide.

According to a further aspect, the collar has a core material and acover material surrounding the core material.

According to a further aspect, the core material is a dimensionallystable, breathable mesh.

According to a further aspect, the cover material is a braided orknitted natural fibre.

According to a further aspect, the tube support includes a tetherextending from the collar, with a connector at one end secured orsecurable to the tube.

According to a further aspect, tether includes a connector at the outerend, with the collar passing through the second connector.

According to a further aspect, the tether includes a first end and asecond end and a connector connecting the first end and the second end,the connector being configured to release upon application of a tensionabove a release tension, wherein the release tension is less than 10 N.

According to a further aspect, the connector of the strap includes afirst portion and a second portion, and in the engaged condition, thefirst portion can swivel relative to the second portion.

According to a further aspect, the connector to engage with the tubecomprises a ring.

According to a further aspect, the patient interface includes a bodyconnected to the seal, and wherein the body includes a nasal sealengaging portion that engages an outward side of the seal, an inletopening and at least one strap engaging portion from which extends aloop strap to secure the interface to the patient.

According to a further aspect, the patient interface includes a softintermediate portion where the loop strap extends from the strapengaging portion, the soft intermediate portion being more rigid thanthe strap but formed of material softer than the material of the body.

According to a further aspect, the body includes two strap engagingportions, each strap engaging portion extending laterally away from theinlet opening, from opposite sides of the inlet opening.

According to a further aspect, each strap engaging portion extends awayfrom the inlet opening in a region where the strap engaging portionoverlaps with the outer wall of the seal.

According to a further aspect, a central portion of the body defines aconvex shape generally matching a convex shape of the outer wall of thebody, with strap engaging portions extending from lateral extremes ofthe central portion, the strap engaging portions extending away from thecentral portion at an angle outwardly aligned relative to the generalconvex shape.

According to a further aspect, the strap engaging portions extend awayfrom the outer wall of the seal with an included angle between themgreater than 30 degrees.

According to a further aspect, the strap engaging portion from the pointwhere it diverges from the outer wall of the seal is between 50% and150% of the length of the equivalent length of the outer wall of theseal.

According to a further aspect, the patient interface includes a bodyengaged with the nasal seal, the body being more rigid than the nasalseal, wherein a lip support depends from the body, and extends beyond anedge of the seal.

According to a further aspect, the lip support includes one or more padsfor engaging against an upper lip portion of the wearer.

According to a further aspect, the lip support includes two dependinglegs, spaced apart at either lateral region of the seal, each legextending beyond a lateral portion of the lower edge of the seal.

According to a further aspect, each leg carries a pad portion orientedto present a face against the upper lip.

According to a further aspect, the legs are moulded to have lowerstiffness about an axis parallel to the lip portion of the wearer whichthey will contact, than about an axis normal to the plane of the lips.

Certain features, aspects and advantages of an embodiment of theinvention comprises headgear for a patient interface, the headgearcomprising: resilient band having a width between 3 mm and 6 mm, astiffness providing an extension of 150 mm with a force less than 2 N, afirst end connected or connectable to a first lateral portion of a mask,and a second end connected or connectable to a second lateral portion ofa mask.

According to a further aspect, the band is between 350 mm and 450 mmlong in its relaxed length.

According to a further aspect, the band is between 60 mm and 110 mmlonger upon application of an extension force of 1 N.

According to a further aspect, the band is constructed from a knitted orbraided yarn, where the yarn includes filaments of a first material andfilaments of a second material of high elasticity but much lowerstiffness than the first material.

According to a further aspect, the band comprises a braided yarn, andthe yarn comprises an elastane filament with a spun wrapper.

According to a further aspect, the band comprises a plurality of braidedthread bundles, and each thread bundle comprises at least two threads,and each thread comprises an elastane core and spun wrapper.

According to a further aspect, the first strap end, the second strap endor both include a soft cover portion, extending 5 mm to 60 mm along thestrap, the soft cover portion being more rigid than the strap.

According to a further aspect, the cover portion is of a softer materialthan the lateral portion of the mask to which it is intended to connect.

According to a further aspect, the headgear includes a first connectorat the first end and a second connector at the second end.

According to a further aspect, the connector includes a resilientlydeformable spring clip engaged in a clip body.

According to a further aspect, the connector includes a coversurrounding and at least substantially encapsulating the clip body and aportion of the band, the cover being more rigid than the band and beingformed of a material softer than the material of the clip body.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface including a strap according toany one or more of the above paragraphs.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface comprising: a nasal sealincluding a face contacting side, the nasal seal being formed of a softflexible material, a body assembled to the nasal seal, the body beingformed of a material more rigid than the nasal seal, and together withthe nasal seal forming an enclosure having an inlet opening and apatient outlet opening, and a lip support depends from the body, andextends beyond an edge of the seal.

According to a further aspect, the lip support includes one or more padsfor engaging against an upper lip portion of the wearer.

According to a further aspect, the lip support includes two dependinglegs, spaced apart at either lateral region of the seal, each legextending beyond a lateral portion of the lower edge of the seal.

According to a further aspect, each leg carries a pad portion orientedto present a face against the upper lip.

According to a further aspect, the legs are moulded to have lowerstiffness about an axis parallel to the lip portion of the wearer whichthey will contact, than about an axis normal to the plane of the lips.

According to a further aspect, the patient interface includes a gasessupply tube depending from the body and a strap extending from theassembled frame and nasal seal in a loop, the strap departing a firstportion of the assembled body and nasal seal at one end and a secondportion of the assembled body and nasal seal at its other end.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface comprising: a mask, a tubedepending from the mask, and a tube support, connected to the tube andincluding a collar fastenable about the neck of a wearer.

According to a further aspect, the collar has a first end portion and asecond end portion, the first end portion and the second end portionincluding a fastening arrangement allowing the end portions to befastened with a selected amount of overlap.

According to a further aspect, the collar includes a third end portionand a fourth end portion and a connector connecting the third endportion to the fourth end portion.

According to a further aspect, the connector is configured to releasethe third end portion from the fourth end portion upon application oftension across the connector greater than a release tension, wherein therelease tension is less than 10 N.

According to a further aspect, the collar is between 30 mm and 60 mmwide.

According to a further aspect, the collar has a core material and acover material surrounding the core material.

According to a further aspect, the core material is a dimensionallystable, breathable mesh.

According to a further aspect, the cover material is a braided orknitted natural fibre.

According to a further aspect, the tube support includes a tetherextending from the collar, with a connector at one end secured orsecurable to the tube.

According to a further aspect, the tether includes a connector at theouter end, with the collar passing through the second connector.

According to a further aspect, the tether includes a first end and asecond end and a connector connecting the first end and the second end,the connector being configured to release upon application of a tensionabove a release tension, wherein the release tension is less than 10 N.

According to a further aspect, the connector of the tether includes afirst portion and a second portion, and in the engaged condition, thefirst portion can swivel relative to the second portion.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface comprising: a nasal sealincluding a face contacting side, the nasal seal being formed of a softflexible material, and including a central portion to extend across thebase of the nose, and a side portion extending from each end of thecentral portion, each side portion extending across the a side of thenose, a body connected to the seal, including a nasal seal engagingportion that engages an outward side of the seal, an inlet opening andat least two strap engaging portions, each strap engaging portionextending laterally away from the inlet opening, from opposite sides ofthe inlet opening, and a strap extending between the strap engagingportions; and wherein a central portion of the body defines a convexshape generally matching a convex shape of the outer wall of the body,with strap engaging portions extending from lateral extremes of thecentral portion, the strap engaging portions extending away from thecentral portion at an angle outwardly aligned relative to the generalconvex shape.

According to a further aspect, the strap engaging portions extend awayfrom the outer wall of the seal with an included angle between themgreater than 30 degrees.

According to a further aspect, the strap engaging portion from the pointwhere it diverges from the outer wall of the seal is between 50% and150% of the length of the equivalent length of the outer wall of theseal.

According to a further aspect, the patient interface includes a softintermediate portion where the loop strap extends from the strapengaging portion, the soft intermediate portion being more rigid thanthe strap but formed of material softer than the material of the body.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface comprising: a single loopheadstrap, a mask for covering at least the nostrils of the user, thesingle loop headstrap extending from the mask at either end, a supplyconduit less than 200 mm long, coupled to the mask for free swivellingmovement including substantial rotation about multiple orthogonal axes.

According to a further aspect, the supply tube is flexible to an extentthat the tube passes the test described herein with reference to FIG.64.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface comprising: a mask for coveringat least the nostrils of the user, a supply port on the mask forreceiving a supply of gases, a bias flow vent on the mask extending froman inside of the mask to an outside of the mask, the bias flow ventdirecting flow in a direction less than 45° to the coronal plane of thehead of a hypothetical wearer, and in a direction generally toward theforehead.

According to a further aspect, the bias flow vent comprises at least onebias flow aperture in a wall of the mask, the portion of the wall havingthe bias flow aperture being aligned more than 45° to the coronal planeof the wearer.

According to a further aspect, the portion of the wall having the biasflow holes is located within a front wall of the mask, and the portionforms a shelf relative to a surrounding portion of the front wall.

According to a further aspect, a plurality of bias flow holes aredistributed in a curve around the upper front portion of the interface.

According to a further aspect, the mask has a general U-shape or V-shapeto wrap around the nose of the user, and the bias flow vent is locatedat the base of the U or V.

According to a further aspect, the seal does not cover the nasal bridgeof the wearer.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface comprising: a frame and a seal,the seal including a patient-facing side with at least one patientopening and a frame-facing side with at least one frame-facing opening,the seal engaging with the frame at a lip defined by the perimeter ofthe frame-facing opening, the frame including a first component part anda second component part, the first component part including a firstportion of a channel for engaging the lip of the seal, the secondcomponent part including a second portion of the channel for engagingthe lip of the seal, the seal being engageable and disengageable fromthe channel with the first and second component parts connected to formthe channel.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface comprising: a frame and a seal,the frame including a first component part and a second component partengaged together, the first component part including a portion forming asocket with surfaces for contacting moving parts of a freely swivellingconnector, the second part comprising a outer cover, with an opening atthe location of the socket of the first part, and the patient interfacefurther including a connector with a joining part projecting past thecover into the socket of the first part to be engaged in the socket ofthe first part for free swivelling movement.

According to a further aspect, the first component is formed from adifferent material to the cover, and the cover and the connector areformed from the same material.

According to a further aspect, the patient interface includes a sealincluding a pair of nasal locators extending from a supple background,each nasal locator including a tip, the nasal locator becoming narrowermoving from the background to the tip, and an opening in the tip of thenasal locator, the opening, and the cross-sectional profile of the tipportion of the nasal locator, being oval or elliptical and having aratio of the length of the major axis to the length of the minor axisgreater than 1.5.

According to a further aspect, the ratio of the length of the major axisto the length of the minor axis is between 1.5 and 3.

According to a further aspect, the tip portion of the nasal locatorincludes a lip adjacent the tip opening, the lip being thickenedrelative to adjacent portions of the tubular portion.

According to a further aspect, the nasal locator includes a dome portionadjacent the background and a tubular portion extending from an apex ofthe dome portion.

According to a further aspect, the tubular portion is tapered, extendingfrom the dome portion to the tip portion.

According to a further aspect, the cross-section of the nasal locator inplanes parallel to the plane of the tip opening is oval or ellipticalthroughout the tubular portion and upper parts of the dome portion.

According to a further aspect, the ratio of the length of the major axisof the oval cross-section to the length of the minor axis of the ovalcross-section reduces, gradually extending from the tip of the tubularportion to the base of the dome portion.

According to a further aspect, the flow projecting axes of the two nasallocators converge at a location between 10 mm or 40 mm from the tips ofthe nasal locators.

According to a further aspect, the central axis of the nasal locator,projected beyond the tips of the locators, converge to become closest ata location 10 mm to 20 mm beyond the tips of the nasal locators.

According to a further aspect, if the tip openings of the nasal locatorsare projected on to the coronal plane of a hypothetical wearer, the ovalshapes of the tip openings are aligned to such that the major axesconverge at an angle between 60 degrees and 120 degrees.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface comprising: a frame and a seal,the seal including a patient-facing side with at least one patientopening and a frame-facing side with at least one frame-facing opening,the seal engaging with the frame at a lip defined by the perimeter ofthe frame-facing opening, the frame including a front face portion inthe region of a swivel connection to a supply conduit, the front faceportion being inclined relative to the coronal plane of the hypotheticalwearer of the interface such that the lower edge of the portion iscloser to the coronal plane than the upper edge of the portion, and theconnector turning flow from an entry to the connector to an exit of theconnector through an angle between 30 degrees and 70 degrees, theconnector and the inclined outward face portion of the mask frametogether allowing for free swivelling movement of the conduit, theconduit to adopt a position more or less parallel to the coronal planeof the hypothetical wearer, and the connector remaining close to theface of the wearer.

According to a further aspect, the connector does not include a biasflow vent.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface comprising: a frame and a seal,the seal including a patient-facing side with at least one patientopening and a frame-facing side with at least one frame-facing opening,the seal engaging with the frame at a lip defined by the perimeter ofthe frame-facing opening, the frame including a supply opening through afront wall of the frame, a ring portion extending from the front wall todefine a passage projecting from the inside surface of the front wall ofthe frame, and a projecting wall passing around the internally open endof the ring portion and engaging the lip of the seal, the front wall ofthe frame and the ring portion, together with other portions of theframe, defining a plenum chamber, with a bias flow vent through a wallof the plenum chamber, and an open area between the ring portion and thestructure of the channel providing a flow path between the interior ofthe seal and the plenum chamber.

According to a further aspect, the bias flow holes are arranged throughthe wall of the frame in an area of the upper portion of the plenumchamber.

According to a further aspect, the ring portion is formed as part of afirst component of the frame, and the front wall of the frame is formedas part of a second component, the two components being secured togetherto define the plenum chamber.

According to a further aspect, the projecting wall comprises a channel,the channel receiving the lip of the seal.

According to a further aspect, the channel follows a closed curved pathof overall width greater than height, such that the plenum chamber ispredominantly formed to either side of the ring portion.

According to a further aspect, the ring portion connects to the upperand lower central portions of the projecting wall and the flow path fromthe seal to the plenum chamber passes either side of the ring portion.

According to a further aspect, the projecting wall is formed as part ofthe same component as the ring portion.

According to a further aspect, the bias flow vent is formed through thefront wall of the second component.

According to a further aspect, the first component includes laterallyprojecting shield portions, the internal surfaces of the shield portionsfitting against outer surfaces of an outward wall of the seal toconstrain the outward deflection of the seal.

According to a further aspect, the second component includes downwardlyand laterally depending stabilisers for stabilising on the upper lipregion of a wearer.

According to a further aspect, the first frame component comprises askeletal frame, with a least a portion of the stabiliser parts of thecomponent comprising an overmoulded soft material.

Certain features, aspects and advantages of an embodiment of theinvention comprises a patient interface including a soft resilient seal,a rigid frame, headgear connecting to the frame, rigid projections atthe connection of the headgear to the frame, the headgear being veryfloppy within 60 mm of the frame, and, between this location and theprojections, a soft portion, more rigid than the floppy portion of theheadgear but made of a softer material than the rigid frame.

According to a further aspect, the projections are alike to prongs, longand slender.

According to a further aspect, the soft portion extends from the generalpath of the prongs.

According to a further aspect, the projection is made up of acombination of a portion of the mask frame and a clip portion of theheadgear.

According to a further aspect, the soft portion is part of the headgear.

According to a further aspect, the headgear is a simple single loopstrap.

According to a further aspect, the projections project laterally beyondthe breadth of the seal.

Certain features, aspects and advantages of an embodiment of theinvention comprises an interface according to any plurality of thepreceding paragraphs.

The term “comprising” is used in the specification and claims, means“consisting at least in part of”. When interpreting a statement in thisspecification and claims that includes “comprising”, features other thanthat or those prefaced by the term may also be present. Related termssuch as “comprise” and “comprises” are to be interpreted in the samemanner.

In this specification where reference has been made to patentspecifications, other external documents, or other sources ofinformation, this is generally for the purpose of providing a contextfor discussing the features of the invention. Unless specifically statedotherwise, reference to such external documents is not to be construedas an admission that such documents, or such sources of information, inany jurisdiction, are prior art, or form part of the common generalknowledge in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

Various forms of the interface will be described with reference to theaccompanying drawings. One form will be described with reference toFIGS. 1A and 1B. Behavioural and sealing characteristics of this examplewill be described with reference to FIGS. 1C to 1E. Additional examplesof the form of the inflating envelope will be described with referenceto FIGS. 1F to 1H. An additional example of an interface with analternative frame is described with reference to FIG. 1I. A furtherexample of an interface with an alternative envelope and frame isdescribed with reference to FIGS. 2A to 2C. Other examples of interfacesand parts of interfaces are described with reference to FIGS. 3 to 65.

FIG. 1A is a view from above of an example interface includinginflatable envelope, supporting frame, and straps.

FIG. 1B is an illustration showing the interface of FIG. 1A in positionon the head of a user.

FIG. 1CA to 1CD are a sequence of illustrations showing inflation of theinflatable envelope. FIG. 1CA shows the seal limp and deflated. FIGS.1CB and 1CC show the envelope with progressively greater inflation. FIG.1CD shows the envelope inflated.

FIGS. 1DA to 1DC show how the envelope retains a seal despitesubstantial vertical movement. FIG. 1DA shows an intended position onthe user's face. FIG. 1DB shows a less than ideal position that mightoccur if the frame was moved upward. FIG. 1DC shows a less than idealposition that might occur if the frame was moved downward.

FIGS. 1EA to 1EC show how the envelope retains a seal despitesubstantial lateral movement. FIG. 1E FIG. 1EA shows an intendedposition on the user's face. FIG. 1EB shows a less than ideal positionthat might occur if the frame was moved to the user's right. FIG. 1ECshows a less than ideal position that might occur if the frame was movedto the user's left.

FIGS. 1FA to 1FE show views of a number of interface variations. Theinterface variations include variation of the shape of the envelope andthe shape of the nasal locators.

FIGS. 1GA to 1GE show views of a number of interface variations. Theinterface variations include variation of the shape of the envelope andthe shape of the nasal locators.

FIGS. 1HA to 1HG show views of a number of interface variations. Theinterface variations include variation of the shape of the envelope,which are illustrated relative to features of a user's face.

FIG. 1I shows an interface with an alternative frame with a stabilisingstrap.

FIGS. 2A and 2B show views of a further embodiment of an interface withan inflatable envelope and frame. The envelope is shaped to wrap aroundthe user's nose in use.

FIG. 2C shows the envelope of FIGS. 2A and 2B with the frame removed.

FIG. 3A is a perspective view of a person wearing a patient interface.

FIG. 3B is a perspective view of the patient interface of FIG. 3Awithout the patient.

FIG. 3C is an exploded view illustrating several components of theinterface of FIG. 3B.

FIGS. 4A to 4C illustrate, from different angles, a seal component ofthe patient interface of FIG. 3B. FIG. 4A shows the seal component froman outward facing side, FIG. 4B shows the seal from a patient-facingside and FIG. 4C shows a side view of the seal.

FIG. 5A is an exploded view of the seal and mask frame showing how theycan be brought together to be assembled.

FIG. 5B is a side view of the interface of FIG. 3B, partiallydisassembled to show the connection of an elbow to the mask frame.

FIG. 5C is a front perspective view of the interface of FIG. 3Billustrating assembly of the elbow with the mask frame, with a gaswashout vent present in the elbow.

FIG. 6 is a front view of the assembled seal and mask frame.

FIG. 7A is a top view of the assembled seal and mask frame.

FIG. 7B is a side view of the seal and frame of FIG. 7A, unsectioned.

FIG. 7C is a view of the patient side of the seal of FIGS. 4A and 4C.

FIG. 7D is a side elevation of the seal of FIG. 7C, sectioned throughline EE.

FIG. 8 is a side view of the seal and mask frame of FIG. 7A takenthrough line DD.

FIG. 9A is a top view of the seal of FIG. 7C, sectioned through line FFof FIG. 7D.

FIG. 9B is a top view of the seal of FIG. 7C, sectioned through line GGof FIG. 7D.

FIGS. 10A to 10C are perspective views illustrating a patient interface.FIG. 10A is a front view, FIG. 10B is a profile view, and FIG. 10C is aback view.

FIGS. 11A to 11H are views of the soft seal component of the interfaceof FIGS. 10A to 10C. FIG. 11A is a top view. FIG. 11B is a front view.FIG. 11C is a rear view taken from a position directly facing the openend of a nasal locator. FIG. 11D is a cross section through section CCin FIG. 11C. FIG. 11E is a cross section through line DD in FIG. 11C.FIG. 11F is a cross section through line EE in FIG. 11E. FIG. 11G is across section through line GG in FIG. 11E. FIG. 11H is a cross sectionthrough line HH in FIG. 11E.

FIGS. 12A to 12H are views of a frame assembly of the interface of FIGS.10A to 10C. FIG. 12A is a front perspective view of the frame assembly.FIG. 12B is a rear perspective view of the frame assembly. FIG. 12C is aside profile of the frame assembly. FIG. 12D is an assembly view of twocomponents of the frame assembly. FIG. 12E is a back view of the frameassembly. FIG. 12F is a front view of the frame assembly. FIG. 12G is across sectional side view taken through line AA of FIG. 12F. FIG. 12H isa cross sectional top view, taken through line BB in FIG. 12F.

FIG. 12I is a rear view of a frame assembly having a different channelpath for securing the lip of the seal.

FIG. 13 shows a further embodiment of an interface with an inflatableseal. The interface includes a seal body, frame, tubing and head strap.

FIG. 14 shows the seal body of the interface of FIG. 13.

FIG. 15 is a perspective view of the frame and seal body of theinterface of FIG. 13.

FIG. 16 is a front view of the frame and seal body of the interface ofFIG. 13.

FIG. 17 is a side view of the frame and seal body of the interface ofFIG. 13.

FIG. 18 is a cross-section of the frame and seal body through BB in FIG.17.

FIG. 19 is an alternative cross-sectional view of the seal body.

FIG. 20 is a cross-section of the seal body through AA of FIG. 16.

FIG. 21 is an alternative embodiment of a seal body of the interface.

FIG. 22 is yet a further embodiment of a seal body of an interface.

FIG. 23 is another embodiment of a seal body of an interface.

FIG. 24 shows a first embodiment of a head strap that may be used withan interface.

FIGS. 24 a and 24 b show two alternative cross-sections of the headstrap of FIG. 24.

FIG. 25 shows a second embodiment of a head strap that may be used withan interface.

FIGS. 25 a and 25 b show two alternative cross-sections of the headstrap of FIG. 25.

FIG. 26 shows a third embodiment of a head strap that may be used withan interface.

FIG. 27 shows a fourth embodiment of a head strap that may be used withan interface.

FIG. 27 a shows the extendible portion of the head strap of FIG. 27 inextended and contracted conditions.

FIG. 28 shows a fifth embodiment of a head strap that may be used withan interface.

FIGS. 29 and 29A shows a sixth embodiment of a head strap that may beused with an interface.

FIG. 30 shows a first embodiment of the connection between a seal bodyand frame of the interface.

FIG. 31 shows a second embodiment of the connection between a seal bodyand frame of the interface.

FIG. 32 shows a third embodiment of the connection between a seal bodyand frame of the interface.

FIG. 33 shows a forth embodiment of the connection between a seal bodyand frame of the interface.

FIG. 34 shows a first embodiment of a brace that may be used with theinterface to fix tubing connected to the interface to the user.

FIG. 35 shows a second embodiment of a brace that may be used with theinterface to fix tubing connected to the interface to the user.

FIG. 36 shows a third embodiment of a brace that may be used with theinterface to fix tubing connected to the interface to the user.

FIG. 37 shows a fourth embodiment of a brace that may be used with theinterface to fix tubing connected to the interface to the user.

FIG. 38 shows a fifth embodiment of a brace that may be used with theinterface to fix tubing connected to the interface to the user.

FIG. 39 shows a sixth embodiment of a brace that may be used with theinterface to fix tubing connected to the interface to the user.

FIG. 40 shows a seventh embodiment of a brace that may be used with theinterface to fix tubing connected to the interface to the user.

FIG. 41 is a perspective view of a supporting collar.

FIG. 42 is a perspective view of a patient wearing the supporting collarof FIG. 41.

FIG. 43 is a perspective view of the collar of FIG. 41 from a differentangle.

FIG. 44 is a front view of a patient wearing the collar of FIG. 41.

FIG. 45 is a top view of the collar of FIG. 41.

FIG. 46 is a top view of a portion of the collar of FIG. 41 illustratinga dome fastener connector.

FIG. 47 is a top view of a portion of the collar including analternative fastener.

FIG. 48 is a top view of a portion of the collar including analternative fastener.

FIG. 49 is a top view of a portion of the collar including a furtheralternative fastener.

FIG. 50A is a side view of a portion of the collar including a securingclip in an engaged configuration.

FIG. 50B is a side view of the portion of the collar from FIG. 50A in adisengaged condition.

FIG. 51A is a side view of a portion of the collar including a securingclip according to an alternative embodiment in a disengaged condition.

FIG. 51B is a side view of the portion of the collar of FIG. 51A in anengaged condition.

FIG. 52 is a perspective view of a tether depending from a portion ofthe collar, with the tether including a quick disconnect connector.

FIG. 53 is a perspective view illustrating a tether depending from thecollar, the tether including a quick disconnect connector which can alsoswivel.

FIG. 54A is a top view of a tether similar to the tether of FIG. 51B,but of minimal length.

FIG. 54B is a top view of the tether of FIG. 54A with the quick releaseconnector disengaged.

FIG. 54C is a side view of the tether of FIG. 54A.

FIG. 55 is an exploded view illustrating connection of a ring of thetether from the supporting collar to a conduit.

FIG. 56 is a perspective view of an interface including an alternativearrangement for supporting the conduit from the patient.

FIG. 57 is a perspective view of a patient wearing an interfaceincluding a further alternative arrangement for supporting the conduiton the patient.

FIG. 58 is a side elevation of a frame and seal, the frame incorporatingdepending lip stabilisers.

FIG. 59 is a top view of the frame and seal of FIG. 58.

FIG. 60 is a front view of the frame and seal of FIG. 58.

FIG. 61 is a perspective view of an interface incorporating the frameand seal of FIG. 58.

FIG. 62 is a graph of tested extension forces against extension ofsample strap materials.

FIGS. 63A to 63C illustrate aspects of a preferred headgear of theinterface of FIGS. 10A to 10C. FIG. 63A is a perspective view of aportion of a headgear, including an end of a headstrap and a connector.FIG. 63B is a top view of the strap and connector. FIG. 63C is a viewshowing both (in cross-section) the connector and the socket of theframe assembly which receives the connector in use.

FIGS. 63D to 63J illustrate another preferred headgear. FIG. 63D shows aportion of the headgear, connector and a portion of the frame assemblyto which it connects. FIG. 63E is a top view of the assembly of FIG.63D. FIG. 63F is a sectional view through line AA of FIG. 63E.

FIG. 63G is a side elevation of the strap portion and connector of FIG.63G. FIG. 63H is a cross-section through line BB of the connector andstrap portion of FIG. 63G. FIG. 63I is an assembly drawing of anexploded view of the strap portion and connector of FIG. 63G. FIG. 63Jis a perspective view of the strap portion and connector of FIG. 63B.

FIG. 64 is a graph of tested extension force against extension ofanother sample strap material.

FIG. 65 is a diagram illustrating a test apparatus for measuring theflexibility of a breathing tube.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

According to one or more examples, an interface includes an inflatableenvelope (that could also be referred to as a bag or balloon) having asupple wall structure. The inflatable envelope has a pair of locatingprotrusions that engage in the nostrils of the user. The locatingprotrusions supply gases flow to the user from inside the envelope. Theenvelope is so supple, and of sufficient dimension and shape, that whenthe inflated envelope is pressed against the face of a user, with thelocating protrusions engaged in the nostrils of the user, the envelopecontacts the surfaces of the user's face (the nose, the upper lip andthe cheeks) and provides a seal.

An example of the interface will be described in detail. Many variationsare possible to both the seal part of the interface and to thesupporting frame and straps. For example, the seal part of the interfacecould be supported by the type of frames and straps that have beendescribed previously for use with nasal masks, or nasal pillowsinterfaces. Though not explicitly described these variations are withinthe scope of certain features, aspects and advantages of an embodimentof the present invention. Many variations on the shape of the envelopeand the shape of the nasal locators also are possible. Some variationsare illustrated in FIGS. 1F to 1H for example but without limitation.

FIG. 1A is a view from above of an example interface including aninflatable envelope, a supporting frame, and straps. FIG. 1B is anillustration showing the interface of FIG. 1A in position on the head202 of a user.

The interface includes a seal body 100. The seal body 100 includes asupple envelope 102. When inflated, the supple envelope 102 has ageneral blob shape with a substantially uniform aspect ratio. Theenvelope has a low wall thickness. The envelope is formed from amaterial having sufficient elasticity and yield strength that thecombination renders the envelope supple. The envelope is capable ofrepeated drastic deformations without failure. Possible materialsinclude latex, vinyl, silicone and polyurethane. Typically, wallthickness would be below about 0.5 mm and could be lower than about 0.2mm.

The seal body includes a pair of nostril locators 104 protruding fromthe envelope. Preferably the nostril locators are formed integral withthe envelope. Each nostril locator includes an outlet aperture forsupplying gas from inside the envelope to a user wearing the interface.

The seal body may broadly be shaped to have a sidewall 108 and a sealsurface 110. The sidewall 108 extends all around the body. In use,either or both of the sidewall 108 and the seal surface 110 may pressagainst surfaces of the user's face to form a seal that conforms aroundthe nose and that surrounds the nostril locators. The nostril locatorsmay or may not be formed to also seal with the nostrils of the user.

The seal body 100 includes an inlet opening at the base, which isapproximately opposite the nostril locators 104 in the illustratedconfiguration.

The seal body may be formed, for example, by coating over a male mould.Coating may be performed by spraying the desired material over the malemould in a sequence of coats, or by dipping the male mould into a bathof the desired material one or more times to build up the desiredthickness. Apertures in the seal body (for example for the outletapertures in the nostril locators) may be subsequently cut. The sealbody may be pressure tested prior to cutting the apertures.

A substantial extent of the seal body or envelope is supple. A regionimmediately adjacent and including the nostril locators and immediatelyadjacent and including the inlet opening are less supple than otherregions. These less supple areas desirably have a shape and can be ofany suitable stiffness. It is preferred that these less supple areas arestiffer and, as such, they may be formed of a thicker less pliantmaterial or they may be formed thicker in the same material as the restof the envelope.

The envelope may be so supple that, when not pressurised with gases, theenvelope, bag or balloon hangs limp and does not hold its shape.However, in some embodiments, it is desired that the envelope retainsome shape when not in use (i.e., when not pressurised). Therefore, theenvelope may have some natural shape. For an example, see the embodimentof FIGS. 2A to 2C.

The seal body 100 is supported by a frame 112. In some configurations,the inlet opening of the seal body is fitted to the frame. In someconfigurations, the inlet opening of the seal body is fitted directly toa conduit extending through the frame.

The frame 112 is preferably a minimal design to provide little visualobstructions, allowing a clear field of view and which allows the userto wear glasses while wearing the interface. Preferably, the frame isformed from an elastomeric material. This allows the frame to flex toconform slightly to the user's face, while still providing support forthe seal body to keep the seal effectively against the face and aroundthe nose of the user.

The frame may be formed by injection moulding, preferably from anelastomeric material such as silicone or polyurethane, for example butwithout limitation. However, more rigid materials may be used.

The illustrated frame presses the inflated seal body against the face ofthe user out to the periphery of the frame. For example, a nasal bridgeof the frame may press the uppermost periphery 200 of the compressedseal against the bridge 216 of the nose of the user. Side peripheralportions of the frame press side peripheral portions of the seal bodyagainst the lower cheeks of the user.

The illustrated frame includes connection points for connecting straps126 to the frame. The strap attachment points provide for anchoring thestraps, and preferably for adjusting the strap lengths.

In other forms, the envelope may include integral strap attachmentpoints. These attachments may be points on the surface of the envelope.However, they could be integral straps or wings formed in the envelopethat extend out either side of the envelope. The strap attachment pointsare similar to those shown in FIG. 1A or 1B and/or described above butare formed on the envelope.

The interface can be supported by a single strap 128 passing around theback of the head. To improve stability of the frame on the face, thestraps 126 can be bifurcated at the forward ends of a strap 128. Eachend of the strap 128 divides at a clip 134 into an upper strap 130 and alower strap 132. The straps may be formed from an elastic or elastomericmaterial. For example, suitable strap materials may include a wovenelastic strip or a narrow strip of foam and fabric, such asBreathoprene™, for example but without limitation. The strap extendingaround the back of the head provides pressure on the mask and helps sealthe envelope to the user's face.

The connection points on the frame may include lower connection points122 for receiving ends of the lower strap 132 and upper connectionpoints 120 for receiving the ends of the upper strap 130. The connectionbetween the frame 112 and the straps may be by any suitable buckle,strap bar or clip, for example but without limitation. In theillustrated embodiment the connection points are provided close to theextreme side limits of the frame.

In the illustrated embodiment of FIGS. 1A and 1B, the frame 112 includeslaterally extended supporting arms 124 that can press on the lower cheekportions 214 of the user, possibly outside the periphery of the sealbody. The side arms 124 preferably are flexible but stiffer than theseal body or straps.

The lower strap connection points are preferably provided at the extremeends of the supporting arms.

The support arms may be provided with some cushioning on their insidesurface to contact the user's face. The cushioning could be formed fromsilicone or from a foam material, for example but without limitation.

A web 218 of elastic material may span between the flexible support arms214 and the upper connection points 122. The web 218 provides support tothe inflated envelope, pushing it against the face to create a mobileseal in the side peripheral region. The web may be thin relative to therest of the mask frame.

A flexible tube 114 extends from the frame 112. The flexible tubedelivers breathable gas. The distal end of the flexible tube 114connects to a main CPAP delivery tube 212, for example, at a connector210. The flexible tube 114 is preferably made of breathable materialsuch as that tube constructions described in U.S. Pat. No. 6,769,431 andU.S. Pat. No. 7,140,366, except the tube 114 is an inspiratory conduitnot an expiratory limb. The contents of each of U.S. Pat. No. 6,769,431and U.S. Pat. No. 7,140,366 are incorporated herein by reference in itsentirety.

A lanyard 204 may be connected to the distal end of the flexible tube114, the connector 210 or the delivery tube 212. The lanyard is to beconnected to the body of the user of the interface. For example, thelanyard may be worn around the neck 206 of the user. The lanyard carriesthe weight of the main delivery tube allowing less pressure to hold theinterface in place. This may allow a single head strap to hold theinterface in place.

The lanyard may connect to the conduit, for example, by a clip 208 thatclips into a corrugation of the conduit. Preferably, the lanyard ortether is connected to the conduit at a location between 10 cm and 50 cmfrom the frame.

A connector 116 may connect the tube and the frame. The connectionmechanism may be any suitable connection. For example but withoutlimitation, this could include a snap fit, hooks in to the silicone,keyhole inserts, over moulding, insert moulding, screw attachments orgluing, or any combination.

The connector 116 may include a limited flow outlet (or bias flowoutlet) 220 for providing gas washout from the interface. The outlet 220may be in the form of a collection of small apertures in the connector.Internally, the connector may include a funnel or extension leading fromthe vent into the mouth of the envelope.

The frame may have any suitable arrangement for securing the envelope.An example is an annular wall extending from the inside of the framearound the perimeter of an opening that extends to the connector 116.The wall includes an outwardly extending lip. The inlet opening of theenvelope engages over the outwardly extending lip of the wall. The inletopening of the envelope is preferably is stretched to fit over the lip.The inlet opening of the envelope may be provided with a thickened orreinforced wall section, for example by rolling up an extended sectionof the envelope.

Alternatively, the envelope may be fitted with one part of a connector(for example but without limitation, by adhesive or over moulding) andthe frame or the end of the conduit may include a complimentaryconnector portion.

The frame could be varied substantially and still provide suitablesupport for the inflatable envelope. The frame could include fewer oradditional supporting arms against the face. The frame could incorporaterigid bodies to provide better support. The frame could incorporate aswivel or ball joint for the flexible conduit to allow rotation throughdifferent angles and orientations. The frame could include mechanisms toadjust size or shape or both to different users. The frame could supportmore than one inflatable envelope.

The interface could include more straps to provide support around theuser's head. The frame and straps could be moulded from a continuousbody of elastomeric material.

FIGS. 1CA to 1CD are a sequence of illustrations showing inflation ofthe inflatable envelope.

FIG. 1CA shows the seal 300 limp and deflated. The side wall and sealportion of the seal body are collapsed toward the inlet perimeter 308.

FIG. 1CB shows the envelope 302 slightly inflated.

FIG. 1CC shows the envelope 304 further inflated.

FIG. 1CD shows the envelope 306 inflated to substantially the final formin which the internal pressure supports the shape against the effect ofgravity. This shows the nostril locators 104 protruding and aligned,ready for positioning in the user's nostrils as the first step indonning the interface.

When inflated without stretch the envelope desirably will not passthrough a circular aperture having a diameter of about 40 mm withoutcontact.

When the envelope is inflated it holds its shape with an internalpressure equivalent to about 3 cm H₂O.

The next stage in donning the interface is to press the frame toward theface to compress the seal body around the region of the nose. The userthen passes the strap over their head to hold the frame in place,pressing against the seal body.

In use, the frame may move relative to the head of the user. This mayresult from movements of the user during sleep, from changing the shapeof their face, from changing the orientation of (and therefore gravityeffects on) the interface, from forces on the conduit connected to theinterface causing tugging at the frame, or from forces directly appliedto the frame or straps.

FIGS. 1DA to 1DC show how the envelope retains a seal despitesubstantial vertical movement of the frame relative to the head. Thewall thickness of the seal body is exaggerated for clarity. The seal isretained by the seal body conforming to the user's face to retain asealing area. The seal body conforms to the user's face due at least inpart to the suppleness and extent of the envelope. In addition, the sealbody conforms to the user's face due at least in part to the treatmentpressure inside the seal body pressing the seal body against the facialcontours.

FIG. 1DA shows a desired position 402 of the seal body relative to theuser's face. The position and orientation of the frame (which is notshown) is indicated by the inlet 400 of the seal body. The upper sealportion 424 of the seal body is wrapped around the tip of the nose 418.The lower seal portion 422 of the seal body is pressed against the upperlip of the user.

FIG. 1DB shows a less desired position 404 of the seal body relative tothe user that might occur if the frame was moved upward as indicated byarrow 408. The more desired position 402 is shown in ghost forcomparison. The upper wall seal and the wall portion 428 have rolledupward. The seal now extends to a higher location 416 on end of thenose. The lower wall seal portion 426 has pealed somewhat away from theupper lip of the user, but abundant supple material still maintains aseal just below the nose at 414.

FIG. 1DC shows a less desired position 406 of the seal body relative tothe user that might occur if the frame was moved downward as indicatedby arrow 410. The more desired position 402 is shown in ghost forcomparison. The upper seal portion 432 has rolled upward, pealing wayfrom the tip of the nose, but the abundant supple material stillmaintains a seal at 420. The lower wall seal portion 430 now covers theupper lip and maintains a seal at 412.

FIGS. 1EA to 1EC show how the envelope retains a seal despitesubstantial lateral movement of the frame relative to the head. The wallthickness of the seal body is exaggerated for clarity. The seal isretained by the seal body conforming to the user's face to retain asealing area. The seal body conforms to the user's face due at least inpart to the suppleness and extent of the envelope. The seal body alsoconforms to the user's face due at least in part to the treatmentpressure inside the seal body pressing the seal body against the facialcontours.

FIG. 1EA shows a desired position 500 of the seal body relative to theuser's face. The position and orientation of the frame (which is notshown) is indicated by the inlet 400 of the seal body. The left andright side seal body portions 510 and 520 respectively cover the cheeksto an equal extent on each side of the nose.

FIG. 1EB shows a less desired position 502 that might occur if the framewas moved to the user's right, as indicated by arrow 506. The left sideportion 510 of the seal has peeled away from the face at region 526 butstill retains a seal in the region of the nares. The right side portionof the seal has rolled out to cover additional area 522 of the rightcheek of the user.

FIG. 1EC shows a less desired position 504 that might occur if the framewas moved to the user's left, as indicated by arrow 508. The right sideportion of the seal has peeled away from the face at region 524, butstill retains a seal in the region of the nares. The left side portion510 of the seal has rolled out to cover additional area 512 of the leftcheek of the user.

One inflating seal arranged and configured in accordance with certainfeatures, aspects and advantages of an embodiment of the presentinvention has been particularly described above. A number of variations,which variations are by no means the limit of variation, are illustratedin FIGS. 1E to 1H. These variations display a number of individualfeatures that may be selected and combined in many combinations. Thecombinations illustrated are selected only for exemplification and othercombinations are also possible.

FIGS. 1FA to 1FE show views of a number of interface variations. Theinterface variations include variation of the shape of the envelope andthe shape of the nasal locators.

The seal body of FIG. 1FA includes nasal locators that are shaped tolocate in the nares. The locators 600 include a bulge 602 between wherethey join the envelope and their outlet ends. The bulge helps secure thelocators within the nares on inflation with internal air pressure. Thenarrower base where they join the envelope increases flexibility.

The seal body of FIG. 1FB includes nasal locators that are shaped tolocate against the nares. The locators 604 include a flange betweenwhere they join the envelope and their outlet ends. The flange isbroader than the nares opening and presses against the lower surfaces ofthe nose. The flange is pressed against the nares by inflation withinternal air pressure. The narrower base where they join the envelopeincreases flexibility. The narrower tip portion 608 locates inside thenares to locate the seal body.

The seal body of FIG. 1FC includes nasal locators 614 that are shaped tolocate in the nares. The locators 614 include an alternating series ofgussets 616 and ridges 618 adjacent their outlet ends. The gussetsassist the locators to expand on inflation with internal air pressure.

The seal body of FIG. 1FD includes nasal locators that are shaped tolocate in the nares. The locators 620 have a wide base 624 adjacent theenvelope and taper to a narrow tip 622. The narrow tip allows for aneasy fit into the nares. The flared base portion 624 provides acomfortable transition to seal in the nares.

The seal body of FIG. 1FD also illustrates the possibility of providingone or more areas 634 of the envelope shaped to deform in a controlledmanner when the seal is compressed against the user's face by the frame.Preferably these areas deform in a predictable way that assists the sealto maintain seal as the frame moves relative to the face.

The seal body of FIG. 1FE includes nasal locators that are shaped tolocate in the nares. The locators 626 include a bulge 628 between wherethey join the envelope and their outlet ends. The bulge helps secure thelocators within the nares on inflation with internal air pressure. Thenarrower base 632 where they join the envelope increases flexibility.The locators 626 also include one or more gussets 630 to assist thelocators to expand when inside the nostrils.

The seal bodies of FIGS. 1FC to 1FD have a substantially triangular sealsurface 610 to increase the amount of supple seal material available tocover the user's nose. The seal bodies of FIGS. 1FA to 1FB have a moreoblong or oval shaped seal surface.

FIGS. 1GA to 1GE show views of a number of interface variations. Theinterface variations include variation of the shape of the envelope andthe shape of the nasal locators.

The seal body 700 of FIG. 1GA includes nasal locators that are shaped tolocate in and against the nares. The locators 720 have a wide flange 722adjacent the envelope and taper to a narrower tip. The tip fits into thenares. The flared portion 722 presses against the lower surfaces of thenose. The nasal locator may have a short stalk recessed inside theenvelope. The stalk provides flexibility.

The seal body 702 of FIG. 1 GB includes nasal locators that are shapedto locate in and against the nares. The locators 724 have a wide flange726 adjacent the envelope and taper to a narrower tip. The tip oflocator 724 is narrower than the tip of locator 720 of FIG. 1 GA. Thenarrow tip fits into the nares. The flared portion 724 presses againstthe lower surfaces of the nose. The nasal locator may have a short stalkrecessed inside the envelope. The stalk provides flexibility.

The seal body 704 of FIG. 1GC is like the seal body of FIG. 1FD exceptfor an ovoid form rather than a triangular form. The locators 730 have awide base adjacent the envelope and taper to a narrow tip. The narrowtip allows for an easy fit into the nares. The flared base portionprovides a comfortable transition to seal in the nares.

The seal body 706 of FIG. 1GD includes nasal locators that are shaped tolocate in the nares. The locators 712 are gently flared to their base.The locators 712 have oval outlet apertures 716, which match the typicalanatomic shape of the nostril entrance. The ovals may be angled relativeto each other. The flared base portion may be steeper on the inwardfacing wall than on the outward facing wall.

The seal body 708 of FIG. 1GE is like that of FIG. 1GD. The nasallocators are shaped to locate in the nares. The locators 714 are gentlyflared to their base. The locators 718 have oval outlet apertures thatmatch the typical anatomic shape of the nostril entrance for a largernose. The ovals may be angled relative to each other. The flared baseportion may be steeper on the inward facing wall than on the outwardfacing wall.

The seal body of FIG. 1GC also illustrates the possibility of providingone or more areas 728 of the envelope shaped to deform in a controlledmanner when the seal is compressed against the user's face by the frame.Preferably, these areas deform in a predictable way that assists theseal to maintain seal as the frame moves relative to the face.

The seal bodies of FIGS. 1GD and 1GE have a substantially triangularseal surface 710 to increase the amount of supple seal materialavailable to cover the user's nose. The seal bodies of FIGS. 1GA to 1GChave a more oblong or oval shaped seal surface.

FIGS. 1HA to 1HG show views of a number of interface variations. Theinterface variations include variation of the shape of the envelope,which are illustrated relative to features of a user's face, in the formthey would take under compression by the interface frame.

The envelope 800 of FIG. 1HA is shaped to have a smaller overall sizewhich seals generally around the bottom of the nose and the nares. Thesmall minimal form still conforms to the user's face due to the CPAPdelivery pressure inside the body. However, the limited lateral andvertical extent of the envelope means it will not retain seal through aslarge of a displacement range as other configurations that areillustrated.

The envelope 802 of FIG. 1HB is shaped to have a larger overall size toencompass more of the area around the nose. The larger extent of theenvelope suggests it will retain seal through larger displacements thanthe seal of FIG. 1HA.

The envelope 804 of FIG. 1HC is shaped to have a larger lateral size toaccommodate users with wider noses and to provide more lateral support.The larger lateral extent 812 of the envelope suggests it will retainthe seal through larger lateral displacements than the seal of FIG. 1HA.Also, the lack of seal over the user's nasal bridge 807 means there isvery limited or no pressure on the user's bridge, thereby increasing theuser's comfort in that area.

The envelope 805 of FIG. 1HD is shaped to be more upwardly extended witha definite protruding portion 814. The protruding portion 814 wraps overthe nose tip and around the sides of the nose to accommodate longernoses.

The envelope 806 of FIG. 1HE is sized to encompass the whole nose havingmore vertical extent 816 and more lateral extent 818 than the envelopeof FIG. 1HA. This envelope may be used with a larger and more extensiveframe to provide a wider seal.

The envelope 808 of FIG. 1HF includes a downwardly extending portion 820that covers the mouth of the user. This downward extension may includean oral interface portion for supplying therapy orally as well as, orinstead of, nasally.

The envelope 810 of FIG. 1HG includes wing portions 822 that exemplifythe possibility that the seal body could provide cushioning underextended parts of the frame. For example, the wing portions couldprovide cushioning under the support members 124 of the frame of FIG.1A.

The described and/or illustrated variations of envelope shape andnostril locating members are provided for the purpose of illustrating anumber of possibilities that could be applied to the inflatable seal.The inflatable seal concept is intended to encompass these and othervariations.

FIG. 1I shows a further alternative embodiment of an interface. Theinterface 900 has a seal body and a supple envelope 901 having anysuitable configuration, including a configuration such as any describedabove.

The envelope 901 is supported by a frame. The illustrated frame 902 cupsabout the envelope 901. Extending above the frame 902 and the envelope901 is a strap. The strap 903 further stabilises the envelope 901.Preferably, the strap reduces the likelihood of the envelope extendingout too far from the user's face and helps the envelope to be pushedagainst the user's face and more particularly the user's nose. The strapcan be made from a flexible material similar to that of the frame butcan be made with any desired stiffness. Therefore, a more stiff materialcould be used or a substantially more flexible material can be usedrelative to the material used for the frame.

The illustrated frame has bias flow holes 904 formed about a connectorfor the conduit, which conduit provides gases to the interface. The biasflow holes 904 provide gas washout from the interface.

A single head strap 905 extends about the user's head in use. The headstrap 905 attaches on either side of the user's head to connectors 906,907 formed in the frame. The connectors 906, 907 are formed in laterallyextending support arms 908, 909 of the frame.

In other forms the strap 903 may be formed in the envelope 901. In thisform, the strap is integrally formed in the envelope and providesadditional stability to the envelope. Therefore, the integral strapeffectively forms an elongate strip in the envelope, wherein the stripextends in an arc above the frame.

FIGS. 2A to 2C show a further example of an interface with an inflatableenvelope, bag or balloon. The interface includes a seal body 940. Theseal body 940 includes a supple envelope 941. The seal body 940 has acurved shape that preferably is configured to substantially match thecontours of a human face. The illustrated seal body 940 has an innersurface 942 and an outer surface 943. The inner surface 942 includesnostril locators 944, 945. The nostril locators 944, 945 each haveoutlets to allow gases to pass to the user. In use, the inner surface942 presses against the user's face and the nostril locators 944, 945extend into or sit about the user's nostrils.

The seal body 940 is shaped to wrap around the user's nose. The sealbody 940 has side portions or wings 946, 947 that extend completely orsubstantially completely over the sides of the user's nose and may alsoextend at least partially over the user's cheeks. The seal body 940 ismissing in the region of the user's nasal bridge. Accordingly, it can besaid that there is a cut out region 948 in the seal body. The cut outregion 948 means the seal body, when in use, does not put directpressure on the user's nasal bridge region, a common area of complaintby users of interfaces that extend over a user's nasal bridge.

The illustrated seal body 940 includes an inlet opening 949. The inletopening 949 is opposite the nostril locators and receives a frame 950.The illustrated frame 950 is curved to match the seal body and providessupport to the seal body. The frame 950 includes a connector 951 thatattaches in use to the tubing (for example tubing 114 as shown in FIGS.1A and 1B) that receives pressurised gases to supply to the user.

The frame 950 is made from a plastics material. The plastics materialmay be a flexible material or maybe a more rigid type material, forexample but without limitation. For example but without limitation, theframe may be made from a polycarbonate or the frame could be made from amore flexible material, such as silicone.

In use, the interface of FIGS. 2A to 2C is supplied with pressurisedgases via tubing and the connector 951 on the frame 950. The gasesinflate the seal body 940 and cause it to press against and about theuser's nose. The nostril locators 944, 945 are caused to seal in orabout the user's nostrils and the pressurised gases pass through thelocator outlets into the user's nostrils.

The illustrated frame or seal body includes at least two strapconnectors similar to those described above. The connectors allow a headstrap to be attached to the interface 940. The head strap will extendabout the back of the user's head and provide additional tension on theinterface to help seal the interface against the user's face.

The seal body can be made from a flexible material. Nonlimiting examplesof possible materials include latex, vinyl, silicone and polyurethane.In a preferred form, the seal body's outer surface is made from athicker material than the inner surface. In this way the seal body has abetter ability to hold a predetermined shape.

FIGS. 3 to 65 illustrate interface configurations that include aninflatable nasal seal having a supple wall structure. FIGS. 1 to 2described above disclose other forms of seals of this type.

The inflatable seal may have a pair of locating protrusions that engagein the nostrils of the user. The locating protrusions supply gases flowto the user from inside the seal. The patient side of the seal may be sosupple, and of sufficient dimension and shape, that when the inflatedseal is pressed against the face of a user with the locating protrusionsengaged in the nostrils of the user, the seal conforms to the surfacesof the user's face (particularly the sides of the nose and the upperlip) and provides a seal. An outwardly facing wall of the seal may bemore rigid, and support the inner wall of the seal in a position wrappedaround the wearer's nose.

The seal is formed from a material having sufficient elasticity andyield strength that the combination renders the envelope supple. Thesupple portion is capable of repeated drastic deformations withoutfailure. Possible materials include latex, vinyl, silicone andpolyurethane, for example but without limitation. Typical wallthicknesses of the supple portions of the seal would be below about 0.5mm and could be lower than about 0.2 mm.

The seal body includes a pair of nasal locators protruding from thepatient facing wall. Preferably, the nasal locators are formed integralwith the seal. Each nasal locator includes an outlet aperture forsupplying gas from inside the envelope to a user wearing the interface.

The seal body includes an inlet opening that is approximately oppositethe nasal locators.

A substantial extent of the seal body or envelope is supple. A regionadjacent and including the nasal locators and a region adjacent andincluding the inlet opening are much stiffer. These areas hold theoverall shape of the seal and can be of any suitable stiffness. Theseareas may be formed of a stiffer material than, or may be formed thickerin the same material as, the rest of the envelope.

The seal is supported by a mask body or frame. The inlet opening of theseal is fitted to the frame or the inlet opening of the seal can befitted directly to a conduit extending through the frame.

The frame is preferably a minimal design to provide little visualobstruction, allowing a substantially clear field of view and allowingthe user to wear glasses while wearing the interface.

The frame may be formed by injection moulding, for example but withoutlimitation, from an elastomeric material, such as silicone orpolyurethane, also for example but without limitation. Alternatively,more rigid materials such as polycarbonate, or polyester, polystyrene ornylon, for example but without limitation, may be used.

The frame can include connection points for connecting straps to theframe. The strap attachment points provide for anchoring the straps.

In other forms, the nasal seal body may include integral strapattachment points. These attachment points may be connection elements onthe surface of the envelope. However, the attachment points could beintegral straps or wings formed in the envelope that extend out eitherside of the envelope.

The interface can be supported by a single strap passing around the backof the head. The strap can be formed from an elastic or elastomericmaterial. For example, suitable strap materials may include a wovenelastic strip or a narrow strip of foam and fabric, such asBreathoprene™, for example but without limitation. The strap extendingaround the back of the head provides pressure on the mask and helps keepthe seal against the user's face.

A preferred strap is described later in this specification.

A flexible tube extends from the frame. The flexible tube deliversbreathable gas. The distal end of the flexible tube connects to the mainCPAP delivery tube.

A connector may connect the tube and the frame. The connection mechanismmay be any suitable connection mechanism. For example but withoutlimitation, the connection mechanism could include a snap fit, hooksinto the silicone, keyhole inserts, over moulding, insert moulding,screw attachments or gluing, or any combination of these or others.

The connector may include a limited flow outlet (or bias flow outlet)for providing gas washout from the interface. The outlet may be in theform of a collection of small apertures in the connector. Internally,the connector may include a funnel or extension leading from the ventinto the mouth of the envelope. Alternatively, the connector may notinclude a bias flow vent.

FIGS. 3A and 3B illustrate an example of patient interface embodimentthat is arranged and configured in accordance with certain features,aspects and advantages of the present invention. For clarity, thepatient interface is shown separate from the patient in FIG. 3B and asworn by a patient in FIG. 3A.

The patient interface 101 broadly includes a mask 103, a strap 104 forsecuring the mask to the patient, a flexible supply conduit 107connecting to the mask 103 and a conduit support structure 109 thatattaches to a patient and that supports the weight of the conduitportion 107 and of any connected conduit supplying gases to the inletend 111 of conduit portion 107.

Particular aspects of this patient interface, and variations on eachaspect, will be (or have already been) discussed with reference to otherFigures. An interface may incorporate some aspects but not otheraspects. For example, an interface might incorporate aspects of the maskwhile using a different arrangement for securing the mask to the user.An interface might include a different mask while using aspects of thestrap to secure that mask to the user. An interface may incorporateaspects of the mask but not make use of a similar, or any, structure forsupporting the weight of the conduit from the body of the patient. Allof these variations are considered within the scope of this application.

Referring to FIG. 3A, the mask 103 fits over the nostrils of the patientand includes lateral portions that curve around either side of the nose.These lateral portions provide form a perimeter seal on the outwardlyfacing surfaces of the flanks of the nose. The strap 105 passes aroundthe user's head in a simple loop above the user's ears.

The conduit portion 107 depends from a central connection 113 at thefront of mask 103. The central connection 113 is preferably a swivelingelbow so that the path of the conduit relative to the positioning of themask on the face of the patient can adapt to the sleeping position ofthe patient. The swiveling elbow may be in the form of a ball joint sothat the elbow can pivot about axes parallel to and perpendicular to itsconnection with the mask.

The illustrated conduit support 109 comprises a collar 115 connectedaround the neck of the user. A tether 117 connects between the collarand the conduit 107.

Some of the component parts of this exemplary interface are illustratedin FIG. 3C. The mask 103 generally includes a seal 301 and a body orframe 303. The seal and body are illustrated in more detail in FIG. 5A.Their engagement will be described in more detail with reference to FIG.5A and FIG. 8.

The body 303 includes a socket 305 and connector portions 307. Thesocket 305 receives an engagement portion 311 of the elbow 333. Theelbow 333 is connected to the end of a length of flexible tubing 315.The other end of flexible tubing 315 is terminated with a cuff 317. Theconnector portions 307 of the mask body 303 engage with connectorportions 321 of the head strap 105. The head strap 105 includes a singlelength 323 of stretchable material. The connector portions 321 areprovided at either end of the length 323.

The collar 115 includes a band 325 of a material intended to becomfortable when worn during periods of sleep. The band includes a firstadjustable connection 327 and a second non-adjustable connection 329. Atthe adjustable connection 327, free ends of the band overlap, and thedegree of this overlap may be varied to a desired amount and fixed atthis desired amount. At the non-adjustable connection 329, free ends ofthe band may simply be secured or released. Once the adjustableconnection 327 has been adjusted, the collar may be opened for fittingto the patient or removal from the client and secured after fitting tothe client, by disconnecting or connecting the non-adjustable connection329. The non-adjustable connection 329 may be a quick release connectorthat disconnects with applied tension within a predetermined range.Thus, the collar will quickly and easily release if desired.

The tether 109 includes a first portion 331 attached to the collar and asecond portion 333 attached to the conduit. These portions preferablyare releasably engaged by another quick release connector, whichpreferably disconnects with application of a tension within apredetermined range.

The tether portion 333 connects to the conduit 315. The tether portion333 includes a portion of the quick release connector and a fitting 337that engages the conduit. The fitting 337 may be an open clip to engagea corrugation of the conduit, to engage a recess of the cuff 317, toengage around the generally cylindrical shape of the conduit, or toengage around a generally cylindrical portion of the cuff.Alternatively, and as illustrated, the portion 337 may comprise a ringthat fits around a portion of the conduit or a portion of the cuff. Inthe illustrated embodiment, the ring 337 is captive between the cuff 317and a connector portion of a swivel 335. The ring fits over a portion339 of the cuff 317 and is held captive by an end portion 341 of theswivel 335, which has a larger diameter than the internal diameter ofthe ring.

The external form of a seal is illustrated in FIGS. 4A to 4C. The seal301 includes a patient-facing side, which is broadly illustrated in FIG.4B, and an outward-facing side, which is broadly illustrated in FIG. 4A.A pair of nasal locators 401 protrude from the patient-facing side.Broadly speaking, the wall of the seal forming the patient-facing sideis very supple with the exception of the nasal locators, the areaimmediately adjacent the nasal locators, or both. Variations in thesuppleness will be described in more detail with reference to the crosssections illustrated in FIG. 7D, FIG. 8 and FIGS. 9A and 9B.

In overall form, the seal has a central portion including nasal locatorson the patient-facing side and an opening 403 on the outward-facingside. The extent of this central portion 407 is broadly indicated bybroken line 409 in FIGS. 4C and 4A. For clarity, broken line 409 is alsoincluded in FIG. 7A, which comprises a top view of the mask portion ofthe interface.

Lateral or side portions 411 extend from the central portion 407. Eachside portion includes an outward face 413, an inward face 415 and aperipheral edge portion 417 that joins the inward face portion and theoutward face portion. The peripheral edge portion 417 extends around atop edge 419, an end edge 423 and a lower edge 421. Accordingly,considered from inside the seal, the side portions 411 resemble apocket.

Each side portion is quite extensive. Preferably, the side portionextends greater than about 10 mm (most preferably greater than about 20mm) or at least a distance of about 70% of the distance separating thecentres of the nostril locators 401 beyond the base of each nostrillocator.

At least the inside wall 415 and the perimeter wall 417 of each sideportion are very supple, so that they can conform to contours of theuser's face, and in particular, to contours of the outside of the sidesof the user's nose. At least portions of the outside facing wall 413 ofthe side portion are also supple, but may be progressively less supplemoving toward the central portion 407.

The central portion 407 of the seal includes the opening 403 to pass agases flow to and from the mask body 303. The opening 403 may includefeatures such as lips and/or channels to engage with features such aschannels and/or lips on the body 303. The opening 403 may be formed withclip portions, or clip portions may be attached to or over-moulded tothe perimeter of the opening 403 to facilitate engagement with the frame303. Typically, the opening 403 will be substantially thicker and morerigid than the supple sealing portions of the seal 301. The opening 403can be at least the size of the interior cross section of the supplyconduit 315. Preferably, and as illustrated, the opening 403 isgenerally commensurate with the extent of the body 303 of the mask, thisextent being generally commensurate with the general width of theinterface and approximately with the width of the nose of the intendedwearer.

The interface can be of small size with the body portion 303 of the maskcurving to follow approximately the contour of the upper lip of thewearer. The seal can be formed such that the opening 403 follows thisapproximate curve, in plan view.

The central portion 407 of the seal extends above and below the opening403. Above the opening 403, and the nostril locators 401, the centralportion includes an outward-facing wall 431, an inward-facing wall 433and a perimeter portion 435. At least the inward-facing wall portion 433and the outward-facing portion 435 are preferably thin and supple.

Below the opening 403, the central portion 407 includes an outer wallportion 441, an inner wall portion 443 and a peripheral portion 445. Atleast the inner wall portion 443 and the peripheral portion 445 arepreferably thin and supple.

In use, the supple interior wall portions above, below and to each sideof the nasal locators are inflated by pressure inside the seal (i.e.,inflated from the flow of gases supplied to the patient interface) topress against the skin of the wearer and conform to contours of theoutside surfaces of the nose of the wearer, to surfaces of the lowerface of the nose of the wearer and to surfaces of the upper lip of thewearer immediately below the nose. Movement of the mask body is notlikely to significantly break this seal because the supple perimeter orperiphery of the seal allows the mask body to move in the direction ofmovement to at least a small extent. The supple perimeter decouples theposition of the nostril locators from the position of the mask body,which decoupling allows the mask body to displace somewhat in at leastone or both of lateral and vertical directions (relative to axes of thepatient's face). The side portions 411 engage the sides of the patient'snose and form an additional seal against them. The side portions 411also support the location of the mask.

The mask body and the seal are illustrated in larger format in FIGS. 5Athrough 5C. As previously described, the seal includes the opening 403and includes structures that can be used to secure the seal to the maskbody. The mask body preferably comprises a socket 503 that is used toconnect with the supply conduit. The mask body also comprises a sealopening 501 that engages with the opening 403 of the seal. In theillustrated configuration, the seal opening 501 and the opening 403 ofthe seal each comprise complementary features that engage the seal andthe mask body together. In the illustrated form, the seal opening 403comprises a connection structure 507 (i.e., lip and channels) and theperiphery of the seal opening 501 of the mask body comprises acomplementary structure 505 (i.e., channels and lips). The connectionstructures 505, 507 advantageously define a gasket-like structure. Thearrangement of channels and lips reduces the likelihood of leaks at thejunction when the seal is properly fitted to the mask body and suppliedwith gases under pressure. Any other suitable connection structure 507can be used to connect the seal and the mask body.

In the mask body, the outlet opening 501 to the seal is directlyopposite the opening of the socket 503 such that the opening 503 issubstantially centrally located. A central side portion 509 extends toeither side of the opening 503. The central side portion 509 may be aplain covering wall that encloses a portion of the opening 403 of theseal. In some configurations, the central side portions 509 may includesmall apertures as part of a gas washout vent.

In the illustrated embodiment, a pair of side arms 511 extend laterallyoutward beyond the extent of the seal opening 501, as best illustratedin FIG. 7A. The side arms 511 can extend beyond the extreme outer widthof the seal. Each side arm 511 comprises a connector portion 513 that isused to connect to the connector portion 321 of the strap. In theillustrated embodiment, the connector portions comprise a securing postwith a perimeter undercut. The strap has a small loop formed at each endwhich stretches over the securing post and engages in the undercut. Thisconnector form is simple and intuitive. Other suitable connector formsalso can be used. For example, each side arm 511 can be provided with aportion (e.g., a male part or female part) of a clip with the strapincluding the mating portion.

As best illustrated in FIG. 7A, the side arms 511 diverge from theoutside wall of the seal, for example at an angle 713 of between about30° and about 80°. A strap secured to the post 513 leaves the side armin a manner illustrated by line 715 in FIG. 7A. Thus, the strap extendsaway from the side arms at a location spaced apart from the seal andspaced apart from the face of the wearer. This is better illustrated bythe relative locations of the tip 717 of the side arm 511 from thecentre line 719 of the interface compared with the seal outermostsurface from the centre line 719 of the interface. The distance 721 fromthe centre line to the tip of the side arm is preferably between about25 mm and about 50 mm, and most preferably about 45 mm. This compareswith the distance 723 between the centre line 719 and the central axisof the nasal locator, which is preferably between about 5 mm and about10 mm, and most preferably about 7 mm. It also compares with theapproximate location of the inner wall surface of the side portion ofthe seal, where it leaves the central portion of the seal. This locationis illustrated by broken line 725 in FIG. 7A. Preferably this separation727 is between about 10 mm and about 20 mm, and most preferably about 15mm. For further comparison, the outermost extent of the side portion isillustrated by broken line 729. The displacement 731 of broken line 729from centre line 719 is preferably between about 15 mm and about 30 mm,and most preferably about 25 mm.

In the front to back direction, the tips 717 preferably are rearward ofthe base of the nasal locators such that at least a portion of the basesof the nasal locators are between the central portion of the mask bodyand a line connecting the tips 717. In some configurations, the entirebase of each of the nasal locates are positioned between the centralportion of the mask body and the line connecting the tips 717. In someconfigurations, the line connecting the tips 717 passes through thenasal locators between the openings (i.e., the portions delivering flowinto the nasal passages) and the bases (i.e., the portions connectingthe nasal locators to the rest of the mask).

With further reference to FIG. 7A, the mask seal may have a broadestexterior extent 741 of between about 30 mm and about 60 mm, and mostpreferably about 50 mm. The seal and mask frame may have an overalldepth 743 of between about 40 mm and about 65 mm, and most preferablyabout 55 mm. Within this depth, the interior space defined by the seal,which wraps around the nose of the user in use, may have a depth 745that is preferably between about 20 mm and about 40 mm, and mostpreferably about 30 mm.

As can be seen from FIG. 7A, the seal curves through a significant arcsuch that the side portions approach generally parallel with each otherand such that the side portions are generally opposed across the spacethat will accommodate the nose. The orientation planes of the sideportions may form together an angle of between about 0° and about 45°(i.e., at 0° the side portions would be parallel) and preferably betweenabout 0° and about 25°. In some configurations, this applies to both theinner wall, and the outer wall, as illustrated in FIGS. 9A and 9B.Preferably this is also true for substantially all of the verticallydisplaced levels within the seal, as illustrated by the different levelsshown in FIGS. 9A and 9B.

The overall plan form of the seal, as illustrated in FIG. 7A, could beconsidered parabolic, half elliptical, half oval or U-shaped. Viewedgenerally, the central portion of the seal defines the width of theseal, with the side portions of the seal extending away from the lateralends of the central portion in a direction substantially parallel witheach other and substantially perpendicular to this width dimension.

FIGS. 5B and 5C also show the connection of the swivel elbow 313 to themask body 303. The illustrated swivel elbow 313 includes a ball portion515 and an opening 517. The outer surface of the ball portion 515 ispreferably a generally frustospherical surface but could be formed withvariation and still achieve a substantial seal with the socket 503.Similarly, the socket 503 preferably is a generally frustosphericalsurface with a slight intruding lip. The structure is best illustratedin FIG. 8, where a lip 803 intrudes slightly relative to the remainderof the generally frustopherical surface 805.

The swivel elbow 313 preferably defines an angle between flow in theconduit, and flow through the connection to the mask of between about 0°and about 90°, preferably between about 30° and about 60°, and mostpreferably about 45°. The elbow may incorporate apertures 519 formingpart or all of a gas washout vent for the patient interface. Theapertures preferably are located on the outside of the bend of theelbow, substantially in the line of the flow path of gases leaving themask.

FIGS. 5B and 5C also illustrate the connector portions 321 of the strap.As illustrated, the connector portions 321 are engaged over posts 513 ofthe mask body.

FIGS. 7A to 7D give context for cross sections illustrated in FIGS. 8,7D, 9A and 9B.

FIG. 7D is a cross section through line EE of the seal of FIG. 7C. FIG.7D illustrates the thicknesses of portions of the seal in the verticalcentre plane of the seal. This shows a thickening of the seal in theregion 731 immediately adjacent and between the nostril locators. Thecross section also illustrates a thickening of the seal in the outerwall portion 431 of the central portion of the seal above the outlet 403and a thickening of the outer wall portion 441 of the central portionbelow the opening 403. These thickened sections are preferably graduallythickened from the thin supple perimeter portions 435, 445 respectivelyto a thickness of about 2 mm to about 4 mm. The supple wall portions,being the peripheral portions 435, 445 and the lower inside wall portion443 and the upper inside wall portion 433, preferably have a wallthickness between about 0.05 mm and about 0.5 mm and most preferablybetween about 0.1 mm and about 0.2 mm.

The portion 731 between the nasal locators preferably has a thicknessbetween about 2 mm and about 0.5 mm and preferably between about 0.8 mmand about 1 mm.

The dimensions are given relevant to a silicone material having a ShoreA hardness of about 40. If the seal is formed of other materials,commensurate alterations of dimension may be possible while retainingsuppleness of the envelope in the regions preferred supple and retainingsufficient stiffness to provide form to the envelope in regions intendedto provide shape.

FIG. 8 is a section through DD of the mask seal and body of FIG. 7A.This illustrates the cross section of the central portion of the seal atthe outward side as illustrated and described already in reference toFIG. 7D but also illustrates the connection of the seal opening to theopening of the mask body. However, the section of FIG. 8 alsoillustrates a preferred cross-sectional form of a nasal locator. Inparticular, the thickness of the material of the wall 807 of the nasallocator is preferably between about 0.5 mm and about 2 mm, and mostpreferably between about 0.8 mm and about 1 mm.

The nasal locator includes a base portion 809 and a nozzle portion 811with a central opening 813. The nozzle portion, which includes theopening 813, generally fits inside the nostril of the user. The baseportion 809 primarily locates the nasal locator at the entrance to thenostril.

FIG. 9A is a section through line GG of FIG. 7D of the seal. This is across section of the seal approximately on a horizontal centre planepassing through the nostril locators. This section shows that the wallportions 807 of the illustrated nostril locators, the immediatelyadjacent region 921 outside the perimeter of the illustrated nostrillocators, and the centre portion 731 between the illustrated nostrillocators all have a thickened wall relative to the more supple wallportions 415, 423 of the side portions of the seal. In particular, theregions immediately adjacent and including the nasal locators preferablyhave a thickness between about 0.5 mm and about 2 mm, and mostpreferably between about 0.8 mm and about 1 mm.

The outer wall portions 413 of the side portions of the seal aresubstantially thicker than the portions adjacent the nostril locators.These portions preferably have a thickness between about 2 mm and about5 mm, and most preferably between about 3 mm and about 5 mm. Theseportions gradually taper in thickness to achieve the supple thicknesswhere they become the peripheral portion 423.

The thickened portion of the outer side wall 413 of the side portionspreferably extends to within about 10 mm of the outermost tip of theside portion.

The thickening and stiffness of these outer side portions 413 providessubstantial form to the seal and provides stability with the seal inplace. The side wall resists outward flexing of the side portions of theseal when the seal is inflated under pressure from the supply while thewall portions 413 will flex outwardly under pressure and have sufficientreaction force to retain the seal wrapped around the nose of the wearer.

The stiffening produced by thicker regions of the seal could be providedby a composite material, or combination of parts. For example, thestiffness could be provided by reinforcement in the silicone, or by aflexible insert of stiff material. The insert of stiff material could beintegrated to the mask body. Preferably, the construction is such thatthe side portions of the seal provide resistance to flexing with aneffective stiffness of at least about 1 N force at the end of thestiffened region to flex the side portion through an angle of about 60°.

FIG. 9B illustrates a further, substantially horizontal plane, above thecross section of FIG. 9A. This cross section is taken through line FF ofFIG. 7D. FIG. 9A again illustrates the thickness of the outer side wallportions 413 of the side portions of the seal relative to the inner sidewall portions 415 and the perimeter portions 423 and relative to thethickness of the upper internal wall portion 433.

Again, the side portions 413 preferably have a thickness between about 2mm and about 5 mm, most preferably between about 3 mm and 5 mm. The moresupple portions 415, 423, 433 have thickness between about 0.05 mm andabout 0.5 mm, and most preferably between about 0.1 mm and about 0.2 mm.

FIGS. 10A to 10C are perspective views illustrating a patient interface.FIG. 10A is a front view, FIG. 10B is a profile view, and FIG. 10C is aback view.

The illustrated interface 1000 is similar to the interface describedwith reference to FIGS. 3A to 3C. The seal 1010 includes manysimilarities to the seal of FIG. 4. The frame assembly 1008 has some ofthe same features as the frame 303 of FIG. 5. Like the interface ofFIGS. 3A to 3C, the interface 1000 has a short depending conduit coupledto the frame assembly 1008 by a ball joint or swivel connection. Also,like the interface of FIGS. 3A to 3C, the interface preferably issecured to the head of the wearer by a single loop strap. This loopstrap may be made of materials described later. The frame assembly mayinclude lip stabilisers as described with reference to FIGS. 58 to 61.

Referring to FIGS. 10A to 10C, the interface 1000 has an overallconfiguration including a frame assembly 1008 and a seal 1010 on theinside of the frame assembly. A supply conduit 1004 depends from theframe assembly and supplies gases to the frame assembly and to the seal.Headgear 1002 connects to the frame assembly to secure the interface tothe head of a user.

The frame assembly includes side portions 1016. Like the assembly ofFIG. 5, the side portions may extend away from the outside wall of theseal (and therefore away from the face of the wearer when in use). Atleast one, and preferably both, side portion 1016 provides forconnection with a connector 1014 of headgear 1002.

The connector 1014 is connected to and terminates an end of the strap1012. Preferably each end of the strap 1012 includes a connector, andeach side portion 1016 includes a matching cooperating connection.

The supply preferably includes a short flexible tube 1026, a supplyconnector 1022 and an interface connector 1006.

Tube 1026 may take many forms. For example the tube 1026 may be astretchy conduit, a springy conduit that is usually short in the relaxedcondition, an extruded corrugated tube or a wound tape tube with aspiral rib. The tube can be resistant to crushing and can allowextensive lateral turning and bending. The tube is preferably betweenabout 50 mm and about 150 mm long.

The interface connector may include a bias flow vent. In the illustratedinterface, no bias flow vent is provided on the connector. The connector1006 preferably includes portions of a swiveling joint 1020 to the frameassembly 1008. The connector preferably includes a portion of a balljoint or swivel joint, and most preferably includes an extending hollowplug portion which extends into a socket of the frame assembly.

With reference to FIG. 10B, the connector preferably turns the supplyflow through an angle of between about 25 degrees and about 75 degrees.Most preferably, the connector turns the flow through an angle ofbetween about 40 degrees and about 60 degrees. This angle combines withthe angle of the front face of the frame assembly in the immediateperiphery of the joint 1020 (e.g., relative to the coronal plane of thewearer) so that the tube 1026 hangs easily below the interface (i.e.,when the user is generally upright), remains close to the user when theuser is lying down, keeps the joint 1020 close to the patient, therebyproviding a lower profile and less leverage on the mask due to forces onthe conduit.

The supply connector 1022 preferably includes a swivel.

The frame assembly 1008 preferably includes a bias flow vent 1018. Biasflow vent 1018 may include at least flow path from the interior of theinterface to ambient surroundings. An interface may be provided for usewith a return flow type ventilator that does not include any bias flowvent.

Where a bias flow vent is included, the bias flow vent may include atleast one aperture extending through the wall defining the frameassembly. In the illustrated interface the bias flow vent 1018 includesa plurality of apertures. The apertures are arranged to direct theoutlet flow of gases predominantly upward relative to the head of thewearer. As used herein, predominantly upward means the gases aredirected in a direction that is more parallel to the plane of the face(or the coronal plane) than perpendicular to the plane of the face, andgenerally in the direction toward the forehead.

As best seen in FIG. 10C, the frame assembly may include dependingsupport portions 1024 that extend below the seal 1010. The dependingsupport portions include pads 1030 that are intended to provide supportonto the upper lip region of the wearer, in the vicinity of thenasolabial folds. On some users, the pads 1030 may extend onto the lowercheek region immediately adjacent the nasolabial folds. The pads areintended to contact the face only when desired to support the seal. Thisaspect of the interface is covered in more detail with reference toFIGS. 58 to 61.

Also in FIG. 10C, the illustrated seal can be seen to include a pair ofnasal locators 1036. Each nasal locator includes an opening, which inuse is disposed within a nostril of the wearer. The nasal locatorsextend from a supple inner wall portion 1042 of the seal.

In the illustrated interface, each nasal locator includes a generallytubular nozzle portion 1040 and a convex base portion 1038. Thegenerally tubular nozzle portion 1040 may be somewhat tapered toward theopen end. The convex base portion may be considered a dome shape.

In some embodiments, the convex base portion extends all of the wayaround the locator and generally surrounds the tubular nozzle portion.In some embodiments, the convex base portion may extend most of the wayaround, but not completely around, the locator. For example, the baseportion may extend continuously about 60% or more of the way around thelocator.

Both the nozzle portion and the base portions of each locator arepreferably oval or elliptical in cross-section. This is illustrated inmore detail in FIGS. 11E to 11H.

FIGS. 11A to 11H are views of the soft seal component of the interfaceof FIGS. 10A to 10C. FIG. 11A is a top view. FIG. 11B is a front view.FIG. 11C is a rear view taken from a position directly facing the openend of a nasal locator. FIG. 11D is a cross section through section CCin FIG. 11C.

From these figures many similarities can be seen to the seal of FIG. 4.The utility and function of the similar features will not be repeated indetail.

In general terms the seal includes an inward facing wall portion and anoutward facing wall portion. The inward facing wall portion forms theseal against the face surfaces of the wearer. The outward facing wallportion connects the seal to the frame assembly and supports the overallshape of the seal. Like the seal of FIG. 4, the general shape of theseal is a U-shape or a V-shape with side portions extending generallyrearward from a central transverse portion.

The outward facing wall portion includes side portions 1032 that are ofgreater cross section than the inward facing wall portion. The inwardfacing wall portion includes nasal locators supported on a generallysupple background 1052. A illustrated supple periphery 1034, 1044connects the outward facing wall portion to the inward facing wallportion around the perimeter.

With particular reference to FIG. 11A and to FIG. 11D, each nasallocator preferably comprises a tubular portion 1040 and a dome portion1038. Furthermore, each illustrated tubular portion terminates in a rim1042 that defines an opening 1050, which is shown in FIG. 11C.

The illustrated tubular portion tapers toward the opening 1050. Thetaper is preferably a linear taper but may be a curved taper or acombination of curved and linear. The surfaces of the dome portion andthe tubular portion meet at an included, obtuse angle, of between about120 degrees and about 160 degrees, for example.

The cross-section of FIG. 11D suggests that the tubular portion 1040 isapproximately frustoconical and that the dome portion 1038 isapproximately frustospherical. However, in each case, the alternatecross section (FIGS. 11F to 11H) is oval rather than circular.Accordingly, the form of the dome is better regarded as ellipsoid. Theform of the tubular portion is better regarded as an elliptic cone.However, in each case the shape need not be a true ellipse, and mayinstead comprise less regular oval shapes, such that the forms might beregarded an ovaloid or ovaloid dome, an ovoid or ovaloid cone or atapering ovoid or ovaloid tube.

The tubular portions of the nasal locators are spaced apart butgenerally aligned such that their axes are generally convergent.Preferably the convergent distance is between about 10 mm and about 40mm from the openings of the nasal locators.

The dome portions of the nasal locators come close together, abut oradjoin at a cleft 1046 at the centreline of the seal. Preferably, thecleft 1046 is formed to allow some freedom of movement of the dome ofone nasal locator relative to the dome of the other nasal locator.

With particular reference to FIGS. 11E to 11H, the oval cross section ofeach nasal locator is shown in more detail. In particular, three crosssections of the nasal locator are shown. These cross-sections are takenon planes that are generally parallel to the plane of the opening of theopen end of the nasal locator.

The cross sections shown the substantially oval form. In particular, theoval or ellipse of the opening 1050 preferably has an aspect ratio ofapproximately 1.8 to 1. The major axis of the oval or ellipse is greaterthan about twice the minor axis, and preferably between about 1.5 timesand about 3 times the minor axis.

The generally oval form is retained throughout the tubular portion andthe dome portions of the nasal locator. However, in the illustratedseal, the absolute difference in the major and minor axes is retainedrather than the ratio. Therefore, the ratio reduces moving from theshape of opening 1050 to the first cross section 1054 spaced toward thebase of the tubular portion. The ratio further reduces moving from crosssection 1054 to cross section 1056 at an intermediate position on thedome portion. The ratio further reduces moving from cross section 1056to cross section 1058 at the base of the dome portion.

By way of example, for the tip opening, the major axis dimension may beabout 9 mm and the minor axis dimension may be about 5 mm. For thecross-section of the tubular portion at EE, the major axis dimension maybe about 13 mm and the minor axis dimension may be about 9 mm.

For the dome portion at GG, the major axis dimension may be about 18 mmand the minor axis dimension may be about 15 mm.

For the dome portion at HH, the major axis dimension may be about 22 mmand the minor axis dimension may be about 18 mm.

As is best illustrated in FIG. 10C, the oval forms of the nasal locatorsare preferably not aligned parallel when viewed from the back of theinterface. In particular, the upper ends of the ovals are closer thanthe lower ends. When projected posteriorly onto a coronal plane of ahypothetical wearer, the major axes of the ovals form an angle ofbetween about 60 degrees and about 120 degrees.

Each nasal locator preferably is provided with a lip 1042 at the openend 1050. The material at the lip 1042 preferably is thicker than thematerial of the rest of the tubular portion, or of the material of theregion of the tubular portion in the near vicinity of the lip. Thethickened lip provides some positive form to the end of the locator whenlocating the locator in the nostril of the wearer. This may be usefulfor the wearer to better feel the end of the locator when fitting theinterface.

FIGS. 11B and 11E also illustrate features of the seal involved insecuring the seal to the frame assembly. As seen in FIG. 11B, theoutward facing portion of the seal includes a major opening for securingwith the frame assembly. The major opening includes a lip 1048 that runsthe perimeter of the opening. The lip may be constituted by the thickerregions of the outward wall of the seal. For example, the lower portionof the lip is illustrated in cross section in FIG. 11E.

At a location, or multiple locations, on the lip, markers or featuresmay be provided to encourage the correct assembly of the seal relativeto the frame assembly. In the illustrated embodiment, the seal isarranged to be detachable from the frame.

For easier positioning, the lip preferably is provided with a protrusionthat engages in a notch of the frame when the seal is correctlypositioned. The lip may be provided with a protrusion 1046 extending ineither or both of the inward and outward direction. In the illustratedembodiment, two protrusions 1046 are provided that engage with notches1074, 1092 of the frame.

The lip of the seal takes the overall form of a bent oval. In otherwords, the lip takes the form of an oval that has been bent so that theends of the oval are curved away from a plane generally tangential tothe central portions of the oval. This can be generally seen in the formof the outward wall portion of the seal in FIG. 11A.

FIGS. 12A to 12H are views of a frame assembly of the interface of FIGS.10A to 10C. FIG. 12A is a front perspective view of the frame assembly.FIG. 12B is a rear perspective view of the frame assembly. FIG. 12C is aside profile of the frame assembly. FIG. 12D is an assembly view of twocomponents of the frame assembly. FIG. 12E is a back view of the frameassembly.

FIG. 12I is a back view of a frame assembly that is of a slightlydifferent configuration. In FIG. 12I, the stabiliser portions are notshown. This illustrates an alternative configuration of the channel forsecuring the seal. The frame assembly may otherwise be formed andassembled in substantially the same manner as the frame assembly ofFIGS. 12A to 12H.

The frame assembly 1008 comprises two major components: a firstcomponent 1070 and a cover 1060. The two components of the frameassembly combine to provide a channel 1096 for securing the lip 1048 ofthe seal. The first component 1070 may include a first portion of thechannel while the cover 1060 provides a second portion of the channel.The component 1070 may provide an inside flange portion 1072 and thecover may provide an outside flange portion 1094. A base portion for thechannel may be provided extending from the flange portion of eitherpart. For example the base portion 1088 may be provided from the flangeportion 1072.

The flange portion 1072 may include a notch 1074 that receives alocating feature of the lip 1048 of the seal. The flange portion 1094may include a notch 1092 that receives an additional locating feature ofthe lip of the seal.

According to the preferred form of the seal and the channel, the channelhas a general outward flare such that portions of the channel onopposite sides of the main opening diverge relative to each other whenprogressing from the base of the channel to the open edge of thechannel. Accordingly, the lip of the seal stretches to pass over theinner flange portion 1072 and the seal is retained in the channel by theelastic tension of the lip.

In the frame assembly of FIGS. 12A to 12H, the channel forms a generalbent ellipse. In the example of FIG. 12I, the channel follows a pathmore like a bent rounded oblong or trapezoid. In particular, the overallpath of the channel is not as broad as the path of the channel in theembodiment of FIGS. 12A to 12H. Furthermore, the channel includescomparatively straight side portions 1220. The side portions 1220converge slightly, extending toward the lower portion 1226, and divergeslightly, extending toward the upper portion 1217. While this assemblyretains the overall bent oval shape, the straightened side portions arefound to improve ease of assembly in comparison with the sharply curvedend portions of the bent ellipse of FIGS. 12A to 12H.

The notch and protrusion alignment preferably is provided adjacent theupper or lower portion of the channel, most preferably adjacent theupper portion of the channel. Thus, the lip 1048 can be seated in thechannel with the correct location and the rest of the lip then isstretched over the inner flange portion 1072.

The first component 1070 may include extensions to carry support pads1030. For example, a lower shield portion may extend in a curve belowthe supply opening of the interface. The lower shield portion mayinclude side portions. The support pads 1030 can be provided on thelower inside surface of the side portions.

An internal surface 1078 of an upper portion of the shield may wraparound to the sides of the interface and may be located outside andadjacent the outward wall of the seal. The upper portions of the shieldcan assist in retaining the form of the seal under internal gasespressures, by constraining outward deflection of the outside of the sealenvelope.

The first component may carry a portion of the swivel connection 1020.Preferably the first component 1070 includes a ring portion 1080 that isopen to the front and the back. The ring portion preferably includessurfaces to engage with surfaces of the supply tube connector.

Preferably, the ring portion 1080 includes an inwardly facingsubstantially spherical surface 1084. The inwardly facing surface 1084may engage an outwardly facing complimentary surface of a ball portionof the supply tube connector. The ball portion of the supply tubeconnector may have in internal passage leading gases from the supplytube through the ring portion 1080.

One advantage of this arrangement is improved available materialchoices. The supply tube connector preferably is made from a differentbase polymer material relative to the ring portion 1080 of the component1070. Different polymer materials working against one another tend toexhibit lower friction and noise than polymers of the same basematerial. The outside cover 1060 can be formed from the same material asthe supply tube connector and thus present an aesthetically pleasingexterior.

For example, the ring portion of component 1070 may be formed from amaterial chosen for its strength and toughness, such as a polycarbonateplastic, and the cover 1060 and supply tube connector formed from aplastic chosen primarily for surface finish and appearance, such as anacetal plastic. The acetal plastic may include a lubricating copolymer,such as PTFE (polytetrafluroethylene).

The ring portion 1080 may also provide features for securing the twocomponents 1060, 1070.

For example the outer surface of ring portion 1080 may be provided withoutwardly facing features, such as depressions or a channel 1082, tocooperate with inwardly facing clips or an inwardly facing annular ridge1087 of the perimeter 1066 of the opening 1068 of the cover 1060. Thisis best illustrated in the cross section in FIG. 12G.

The outer periphery of the cover 1060 may blend into the surfaces of thecomponent 1070 in some parts. For example, the lower curved edge of thecover 1060 may abut the upper curved edge of the lower shield of thecomponent 1070. This is indicated at 1081 in FIG. 12G. A similarabutting edge at the side portions is indicated at 1081 in FIG. 12H.

The components 1060, 1070 may form an outlet plenum adjacent the biasflow vent 1018. This is best understood by considering the exploded viewof FIG. 12D, the rear view of FIG. 12B, and the cross sections of FIGS.12G and 12H. The plenum 1079 is defined between a bent oval frameportion 1072 of component 1070 and the inside surface of the cover 1060in the vicinity of the aperture 1068.

The illustrated openings 1086 into the plenum 1079 are defined by therear edge of the ring portion 1080 and by the oval frame portion 1073.Gases flowing from the seal to the bias flow vent pass through theseopenings. The inside surface 1098 of the flange 1072 of oval frame 1073preferably converges moving toward the plenum, which defines a flowdirecting surface acting somewhat like a funnel.

The holes of the bias flow vent 1018 lead from the plenum 1079.

The ring portion 1080 opens essentially centrally through the oval frameportion 1073. This divides the flow into the seal and the flow out ofthe seal essentially at a location directly adjacent the open end of theseal.

The ring portion may be supported in this position by one or moresupporting struts 1076, or by regions at the top and bottom where thering and oval frame portion come together.

The bias flow holes 1097 are arranged in a curve around the upperportion 1089 of the plenum chamber 1079. This upper portion is quiteconfined in the location illustrated in FIG. 12G, immediately above thering portion 1080, but more open to either side.

To provide an upward exit flow (generally parallel to the coronal planeof the wearer), the bias flow holes may be arranged in a shelf portion1099 of the wall of the cover 1060.

The lower shield portion of the component 1060 may include a softcovering 1085, such as an overmoulded layer of a soft biocompatiblematerial, over a more rigid skeleton or frame 1083. A preferred coveringwould be, for example but without limitation, a thermoplastic elastomer,a polyurethane foam, or a silicone elastomer. The skeleton or frame 1083of the component 1060 may be formed from a copolymer including an amountof a plastic material that bonds strongly with the covering material.For example but without limitation, the frame 1083 may be formed from apolycarbonate siloxane copolymer. The siloxane contributes chemicalresistance and improves the bonding of the overmoulded silicone cover.

Extreme side portions 1016 of the cover 1060 diverge from the outersurfaces of the shield of component 1070. The side portions 1016 end insockets 1062 that receive connectors of the headgear strap.

FIGS. 13 to 20 show a further embodiment of an interface with a wraparound inflating seal. The interface 1100 includes a seal body 1101 andframe 1102.

Attached to the frame 1102 is tubing 1112 that is attached to a gasessupply apparatus. The tubing supplies gases to the mask frame and seal.The tubing 1112 may be tethered to the user (i.e., the person wearingthe interface 1100) by a lanyard 1113. In use, the lanyard 1113 extendsabout the user's neck. The lanyard 1113 is affixed to the tube by anysuitable mechanism, however, shown is a c-shaped clip 1114 attached tothe lanyard 1113 that clips about the tubing.

The interface 1100 is held in place over the user's nose by way of ahead strap 1114. The strap preferably is made of a flexible typematerial, such as silicone or a laminated material well known in the artof head gear straps. Each end of the strap 1114 preferably is fitted toa clip 1116 that attaches to a corresponding eyelet 1117 formed in orattached to the seal body 1101. The strap may be a flat moulded siliconestrap, a small hollow silicone tube, or other suitable configuration.

The frame 1102 may have formed in it a plurality of bias flow holes 1115to allow for exhausting of the user's exhalated gases from theinterface. Alternatively, bias flow holes may be formed in the seal body1101 to allow for exhausting of gases.

The seal body 1101 is a supple or inflatable type seal. The illustratedseal body 1101 is curved in shape to match the contours of a human faceand extends about the user's nose, substantially wrapping the user'snose. The seal body 1101 preferably extends completely or substantiallycompletely over the side of the user's nose and may also extend at leastpartially over the user's cheeks. The seal 1101 comprises an inner wallwith an inner wall with an inner surface 1103 and an exterior wall withan outer surface 1104. Projecting from the inner surface 1103 are nasallocators 1105, 1106, each with outlets 1107, 1108.

As with the embodiment of FIGS. 10 to 12, the seal body 1101 includes aninlet opening 1109 that is opposite the nasal locators 1105, 1106 andthat receives the frame 1102.

The seal 1101 has a variable wall thickness such that there is someenhanced rigidity around the portions of the seal that project outwardand such that there is some flexibility between the nasal locators 1105,1106 and a periphery 1110 of the inlet opening 1109 of the seal. Thismeans there is a decoupling effect between the nasal locators 1105, 1106and the inlet periphery 1110, and subsequently to the mask frame 1102.This will mean that some movement of the mask frame will be possiblewithout disrupting the sealing of the nasal locators 1105, 1106 on or inthe user's nostrils.

As can be seen in FIG. 18, the inlet periphery 1110, which defines thegases inlet 1105 to the seal, has a substantially thick cross-section.This provides enhanced relative rigidity to the inlet periphery 1110.Similarly, the nasal locators 1105, 1106 have a substantially thickcross-section. However, the thickness of the nasal locators may notnecessarily be as thick as or thicker than the inlet periphery 1110. Inthe illustrated form, the thickness of the nasal locators is less thanthat of the inlet periphery.

The areas between the inlet periphery 1110 and the nasal locators 1105,1106 is preferably thinner in cross-section than both nasal locationsand the inlet periphery. For example, in FIG. 18 the length of the seal1101 between X and Y is formed to be substantially thinner incross-section than either the inlet periphery or the nasal locators.This means this length is more flexible, effectively allowing moremovement of the nasal locators 1105, 1106. Furthermore, as the lengthbetween X and Y, including an outer periphery 1111, is thinner in crosssection, the seal will easily inflate to assist in the sealing of theseal about the user's nose.

As shown in FIG. 18, preferably a region 1118 of the envelope adjacentto the base or root of each nasal locator has a thickened cross section.As shown, the length or region 1119 of the seal between the region 1118and the thickened inlet periphery 1110 can be formed to be substantiallythinner in cross-section than either the inlet periphery 1110, the nasallocators 1105, 1106 or the region 1118.

In some configurations, the envelope includes a thickened region 1118adjacent the root of the nasal locators and the thickness of the crosssection of the nasal locators is not thickened. For example, thethickness of the cross section of the nasal locators may be similar tothe thickness of the envelope region 1119 extending between the region1118 adjacent the nasal locators and the inlet periphery 1110. Thethickened region 1118 adjacent the root of the nasal locators reducesthe likelihood of deformation or excessive ballooning of the base of thenasal locators under typical CPAP pressure. However, the thinner wall ofthe nasal locators 1105, 1106 in this embodiment may balloon to somedegree under CPAP pressure.

Preferably, the seal 1101 is formed from silicone with a Shore Ahardness of about 40. Alternatively, other materials with similarproperties may be used. For silicone with a Shore A hardness of 40, orother material with similar properties, the thickness of the envelopregion 1119 extending between the nasal locators and the inlet peripheryis less than approximately 0.5 mm. Preferably this region 1119 has athickness of about 0.1 mm to about 0.2 mm. Alternatively this region1119 of the envelope may have a thickness of less than about 0.1 mm, forexample about 0.05 mm.

The thickness of the region 1118 adjacent the base of the nasal locatorspreferably has a thickness of less than about 2 mm. Preferably, thethickness of the region 1118 adjacent the base of the nasal locators isabout 0.8 mm to about 1.0 mm. Alternatively, the thickness of the region1118 adjacent the base of the nasal locators may be less than about 0.8mm, for example about 0.5 mm.

The thickness of the region adjacent the inlet periphery is about 3 mmto about 5 mm, but could be thinner such as, for example, about 2 mm.

The nasal locators have a thickness of less than about 2 mm. In thepreferred embodiment, the nasal locators have a thickness of about 0.8mm to about 1.0 mm. Alternatively, the thickness of the nasal locatorsmay be less than about 0.8 mm such as, for example, about 0.5 mm.

In the alternative embodiment described above, the thickness of thenasal locators is similar to the thickness of the envelope region 1119extending between the nasal locators and the inlet periphery. In thisembodiment, the nasal locators have a preferred thickness of about 0.1mm to about 0.2 mm. Alternatively, the thickness of the nasal locatorsmay be less than about 0.2 mm such as, for example, about 0.05 mm.

Preferably the change in thickness from one region of the seal toanother occurs gradually. For example, the thickness of the seal changesgradually from thickened portion 1118 to thinner portion 1119.Similarly, the thickness of the seal changes gradually from thickenedportion 1110 to thinner portion 1119.

Referring now to FIG. 20, which shows the seal 1101 in cross-sectionthrough AA of FIG. 16. This figure shows an alternative view of the seal1101 showing the varying thicknesses of parts of the seal. Inparticular, the inlet periphery 1110 and nasal locators 1106, 1108 arethick in cross-section compared to the outer periphery 1111. At least inthe lateral direction, the thickened region 1110 adjacent the inletextends for at least half of the distance from the inlet to the outerperipheral edge 1121. In the upward direction the thickened regionextends at least half the distance from the inlet to the top peripheraledge 1123. In the downward direction the thickened region extends atleast half the distance to a lower face portion 1125. The areas of theseal between the nasal locators 1106, 1108, generally indicated as 1112,are also thicker in cross-section to provide additional stability inthese areas for the nasal locators.

In FIG. 21, an alternative embodiment of the seal is shown. In thisalternative embodiment the areas between the nasal locators, indicatedas 1113, are substantially thinner in cross-section than that of theinlet periphery 1110 and the nasal locators 1106, 1108. Thisconfiguration would provide additional flexibility between the nasallocators 1106, 1108.

A yet further embodiment of a seal, which is arranged and configured inaccordance with certain features, aspects and advantages of the presentinvention, is shown in FIG. 22. Here the seal is an inflatable type butthe seal extends down to occlude the user's mouth in use. This seal 1200has nasal locators 1201, 1202 and is received in a frame similar to thatdescribed in any of the embodiments detailed above. The seal 1200 has anextension 1203 that goes over the user's mouth to create a seal and toreduce mouth leaks.

Another embodiment of a seal, which is arranged and configured inaccordance with certain features, aspects and advantages of the presentinvention, is shown in FIG. 23. This seal 1300 is of the same generalform as that in FIG. 22, with nasal locators 1301, 1302 and a mouthcovering extension 1203, but includes an outlet 1304 directed to theuser's mouth to allow gases to be delivered simultaneously to the user'smouth as well as the user's nasal passages through the nasal locators1301, 1302.

FIGS. 24 to 29 show various head straps that might be used with any ofthe embodiments of the interfaces described herein.

FIG. 24 shows a single head strap 1402 attached to the interface 1400,particularly to the flexible and inflatable seal 1401, by any suitablestructure. The strap 1402 may be a hollow tube 1402 as shown in FIG. 24a or a solid tube 1402′ as shown in FIG. 24 b. The hollow tube could,for example, be an extended silicone tube, with a diameter between about3 mm and about 6 mm and, where hollow, the tube may have a wallthickness of about 0.2 mm to about 1 mm.

FIG. 25 shows a single head strap 1410 attached to the interface 1400,particularly to the flexible and inflatable seal 1401 by any suitablestructure. The strap 1410 may be a hollow elongated tube 1410 as shownin FIG. 25 a or a solid elongated tube 1410′ as shown in FIG. 25 b. Thestrap is preferably thinner in width at its ends 1411, 1412 that attachto the seal 1401 and thicker in width at its midpoint that sits at theback of the user's head in use.

FIG. 26 shows a double head strap 1420 attached to the interface 1400.The strap 1420 extends about the user's ears and has two attachmentpoints on each side of the seal 1401 where the strap attaches to theseal 1401.

FIGS. 27 and 27 a show an extendible head strap 1430 attached to theinterface 1400. The strap 1430 has an area 1431 that can be extended andcontracted to better fit the strap to the user's head.

FIG. 28 shows an alternative head strap 1440 attached to the interface1400, particularly to the seal 1401. The head strap 1440 preferablyincludes side straps 1441 having areas of rigidity 1442, 1443, toprovide additional stability to the side straps 1441. The head strap1440 also preferably includes a top strap 1444 and a back strap 1445that each extends over the head or behind the head respectively. Thishead strap is detailed further in U.S. patent application Ser. No.12/307,993, which is hereby incorporated by reference in its entirety.

FIGS. 29 and 29 a shows yet a further alternative head strap 1450attached to the interface 1400, particularly to the seal 1401. The headstrap 1450 is curved and has partitions 1451 that provide additionalsupport or rigidity to the strap.

The head straps detailed above may be formed of any appropriatematerial, such as, flexible plastics, silicone, laminated fabrics, orother appropriate materials, for example but without limitation.

FIGS. 30 to 33 show various ways in which an interface frame may beattached to an inflatable seal body. In FIG. 30, the seal body 1500includes overmoulded or bonded rigid plastic barbs 1502. The barbs 1502clip into correspondingly shaped recesses 1503 formed in the frame 1501and hold the seal body 1500 in sealing engagement with the frame 1501.

In FIG. 31, the seal body 1500 has a periphery 1512 that is formed witha overmoulded or bonded rigid plastic looped clip 1513 that clips to theframe 1501. Further details of such a clipping mechanism are describedin U.S. patent application Ser. No. 12/502,528, which is herebyincorporated by reference in its entirety.

As shown in FIG. 32, the seal body 1500 may have an inlet 1522 that hasa stretch interference fit about the frame 1501. The frame preferablyhas a groove 1523 and a raised edge 1524 that allows the inlet 1522 toengage with the frame.

As shown in FIG. 33, a seal body 1500 may be permanently attached to theframe 1501 by overmoulding or by bonding, for example but withoutlimitation.

FIGS. 34 to 40 illustrate various ways in which the tubing (1112, seeFIG. 13) extending from the interface 1100 may be secured to a user. Theadvantage of securing the tubing to the user is to take at least aportion of the weight of the tubing off of the interface, reducing thepossibility of the interface being pulled from the user's face. Each ofthe braces described below can be made from fabric straps. It ispreferred that the fabric is a breathable type material but otherappropriate fabrics may be used. Preferably, the tubing is fixed to thebrace by way of a clip or pin, for example but without limitation.

In FIG. 34, a brace 1600 is shown that is made from a looped strap offabric that in use is placed about the user's head and one shoulder.

In FIG. 35, a brace 1610 is shown that is formed in a central crossacross the user's chest and that is braced around each of the user'sarms.

In FIG. 36, a brace 1620 is shown that has a central cross of strapsacross the user's chest but that is braced across the user's neck andback.

In FIG. 37, a brace 1630 is shown that could be used to secure tubing tothe user wherein the brace 1630 is formed from the looped strap thatextends about the user's chest and under their arms.

As shown in FIG. 38 or 39, a brace 1640 may additionally include twoshoulder straps 1641, 1642 or simply one shoulder strap 1643.

As shown in FIG. 40, a brace 1650 may be used that fits in use about theuser's shoulder or upper arm.

Additional tube support arrangements will be described with reference toFIGS. 41 to 57. FIGS. 41 to 51 describe a supporting collar intended tobe worn around the neck of the user, and to which the tube may besupported by a tether. FIGS. 52 to 55 describe aspects of a tether thatmight be used with such a collar, or that might be used with otherarrangements for securing one end of the tether to the patient. FIGS. 56and 57 illustrate two such arrangements for securing a tether to thepatient. FIGS. 34 to 40 illustrate other arrangements for securing sucha tether to the patient.

FIGS. 41 to 45 illustrate in further detail the collar previouslydescribed in broad terms in relation to FIGS. 3A to 3C. The illustratedcollar includes an adjustable connection 327 and a secondary connection329. The adjustable connection operates between a first end of thecollar 4100 and a second end 4102. The adjustable connection 327 allowsthe user to set the amount of overlap of the ends 4100 and 4102. FIGS.41 to 45 illustrate an adjustable connection 327 in the form of a domefastener system. One fastener portion 4104 is fixed to the first strapend 4100. A number of complementary fastener portions 4106 are providedspaced along the second strap end 4102. Engaging the fastener 4104 withone of the series of fastener portions 4106 sets the overlap of end 4100relative to end 4102. The fastener portions 4106 may be spaced atintervals between about 2 cm and about 5 cm, preferably between about 3cm to about 4 cm. This provides a degree of variation in thecircumference of the collar in increments of between about 3 cm andabout 4 cm.

Preferably the outer overlapping end 4100 includes a single connectorportion and the inner strap end includes a series of outwardly-facingsecond connector portions. According to this arrangement, no connectorportion faces toward the patient neck. Accordingly, the internal surfaceof the collar is free of projections.

The connector portions may be portions of, for example, a dome fastenerof known type.

The extreme end of inner end 4102 may include an outwardly projectingloop engaging over the overlapping portion of the collar strap. Thisloop 4302, shown only in FIG. 43, would align the free end ofunderlapping end 4102 with the overlapping portion of the collar whenthe collar is set on tighter sizes.

Alternative connectors for the adjustable connection are illustrated inFIGS. 46 to 49. The dome fastener connection is illustrated in moredetail in FIG. 46.

An alternative fastener using engaging magnets is illustrated in FIG.47. The outer strap end 4702 includes an inwardly-facing magnet portion4704. The inner strap end 4706 includes an outwardly-facing magnetportion 4708. The inwardly-facing magnet portion 4704 preferably ismagnetized to a first polarity facing inwards. The outwardly-facingmagnet portion 4708 is preferably magnetized with a complementarypolarity facing outwards. A series of outwardly-facing magnets 4708would be spaced along the outer surface of the inner strap portion 4706.

The magnet portions may be fixed to a base portion 4710 which in turnmay be fixed to the strap. For example, the magnets may be glued to asubstrate material that can be stitched to the strap. Alternatively,magnets might be moulded to include holes to allow the magnets to bedirectly stitched to the strap.

The magnet 4704 could be replaced by a magnetic material which would beattracted by magnets 4708 but not be a magnet itself. Alternatively,magnets 4708 could be replaced by portions of a material that ismagnetic but not itself a magnet. By way of example, the magnets may beferrite or rare earth, while magnetic materials might be small sectionsof steel. Ferrite powder bonded with a flexible polymer may allow themagnets to be flexible while maintaining sufficient strength to securethe collar.

FIG. 48 illustrates the adjustable connection being made by a hook andloop fastener system. For example, the outer end portion 4802 mayinclude a short section 4804 of a material with projecting hooks. Theinner strap end 4806 may include an outwardly-facing section 4808covered with loops to which the hooks may engage and disengage. Suitablehooks and loop fastener material is sold under the Velcro brand.

The outwardly facing loop material may be stitched to the collar strap,or the collar strap may be formed from a material that integrallyincludes the loops. The length of the loop portion 4808 is much greaterthan the length of the hook portion 4804 and preferably extends a lengthequivalent to the adjustment desired to be available to the collar. Forexample, the loop fastener material would have a length of about 15 cmalong the collar strap.

FIG. 49 illustrates an alternative mechanical fastener similar to thedome fastener. This type of dome fastener includes a smaller receivingaperture 4902 on the female portion and smaller projecting pins 4904 onthe male portion.

Referring back to FIGS. 43 to 45, the collar preferably includes asecond releasable connection 329 between a third end 4302 and a fourthend 4304. Thus, the overall ring of the collar is divided into twoseparate strap sections. Each strap section includes at one end part ofthe adjustable connections 327 and at the other end part of the secondconnection 329.

Preferably this second connection is not adjustable. This secondconnection 329 is intended to be engaged and disengaged at each use ofthe collar. The adjustable connection can be adjusted to the correctlength and set, and the second connection 329 can be used to secure andrelease the collar.

This second connection 329 may be formed by any suitable means,including the examples illustrated in FIGS. 46 to 49, or including aplain releasable fastening clip such as illustrated in FIGS. 50A and 50B(50A in the connected condition and 50B in the open condition), or abreakaway connector which releases upon application of tension in apredetermined range.

The connection 329 illustrated in FIG. 45 includes a breakaway connectorhaving a first body portion 4502 secured to strap end 4302 and a secondbody portion 4504 secured to fourth strap end 4304. The first and secondbody portions each include a projecting tang and a socket. Theprojecting tang of one body is complementary with the socket of theother body. The projecting tang and socket preferably have aninterference fit. The amount of interference and the force required topull the tang from the socket defines the release force for thebreakaway clip.

This preferred breakaway clip is illustrated in more detail in FIGS. 51Aand 51B. In FIG. 51A, the clip is illustrated in the open configurationwhere a tang 5102 projects from each clip body portion and each tang5102 includes a small lateral projection 5104. The socket in each bodyportion of the clip includes a lateral aperture 5106. When the tang 5102is pushed into the socket, the projection 5104 extends into the aperture5106. The interference fit is provided by engagement of the projection5104 in the aperture 5106. This connector is shown in its engagedcondition in FIG. 51B.

Referring again to FIGS. 41 to 45, a tether extends from the collar. Thetether 4112 is connected with the collar at one end and to an engagingclip 4114 at its free end. The engaging clip 4114 allows connection withthe supply conduit for the patient interface. The engaging clip 4114 isillustrated in greater detail in FIG. 55, where an enlarged view of itsfitting with the cuff of the conduit is illustrated. The preferredconnector includes an open ring which fits over a sleeve portion of thecuff and is held in place between a flange 5502 of the cuff and a flange5504 of a swivel conduit connected to the cuff.

The preferred tether includes a breakaway clip at some position alongits length between the connection to the collar and the conduitconnector. The breakaway connector may be of the form described alreadywith reference to FIGS. 51A and 51B. That form of breakaway connector isillustrated in FIGS. 52, 54A and 54B.

The breakaway connector may also include a swivel, such that the collardoes not need to be correctly oriented relative to the conduit beforedonning the patient interface. In this case, the breakaway connector mayinclude a socket portion 5302 and a male portion 5304, with the maleportion 5304 being rotationally symmetric. For example, the male portion5304 may include a projecting knob 5306 with an enlarged end 5308. Thesocket 5302 would include projecting portions or an annular projectingportion around the internal circumference adjacent the open end. Thesocket 5302 may be made in two pieces subsequently secured together toproduce this projecting lip or lips. The socket portion 5302 may be openat its other end 5310 so that the connector portion 5302 can be formedin one piece. This end may accommodate an end of a strap portion 5312 ofthe tether.

A swivel may be included at another location along the tether.

Preferably, the tether is formed with a sliding connector 5202 at oneend for connection over the collar. The sliding connector 5202preferably comprises a moulded loop including straight sections oneither side of the web of the collar and joined by transverse sectionsabove and below the collar edge. The loop preferably has a moderatelytight fit on the collar so that once moved into a position, it tends tostay in that position but can be moved along the collar upon applicationof sufficient force. The loop 5202 essentially mirrors the profile ofthe web of the collar. A tether portion may extend from the loop 5202,preferably being integrally formed with the loop 5202. Preferably, thetether portion and the loop are formed from a flexible resilientmaterial, such as silicone, for example but without limitation.

Another tether portion extends from the quick release connector to theconduit in engagement clip. Again, this may be formed of any suitablematerial, preferably flexible and preferably a silicone material, forexample but without limitation.

The tether may be of fixed or adjustable length. Preferably, the tethermay be provided in multiple lengths for selection by a patient. Thetether may be of a length between about 3 cm and about 15 cm. A tetherat approximately 3 cm is illustrated in FIGS. 54A to 54B, the tetherincluding limited, if any, strap portions. This tether is mostly made byits loop connector to the collar, by the quick release connector and byits connection to the conduit connector.

A longer tether is illustrated in FIG. 52 and in FIG. 53, including asubstantial strap portion between the connecting loop 5202 and the quickrelease connector and another substantial strap portion between thequick release connector and the conduit connector. These portions of thetether could be interchanged so that, for example, the strap portion ofthe tether could be provided entirely to one side or other of thebreakaway connector.

FIG. 56 illustrates an alternative support arrangement to the use of acollar. The tether 5602 terminates in a clip 5604 instead of terminatingat a connector for the collar. The clip 5604, preferably in the form ofa type of peg, alligator clip or other arrangement having gripping jaws,can attach to the neckline or other convenient portion of clothing wornby the patient. Alternative, the tether may be terminated at a connectorfor connecting to brace structures to be worn by the patient asdescribed earlier.

The tether may or may not include a breakaway connector.

FIG. 57 illustrates another alternative for connection to clothing 5702on the patient. This illustrates the push clip 5704 connected to thecollar line of the clothing and including a breakaway connector 5706.

The preferred collar is constructed from materials comfortable to thewearer. In the simplest form, the collar might be, for example butwithout limitation, a strap of a soft, flexible material havingsufficient stiffness to hold the general collar form, sufficientstrength to resist any substantial extension or stretching andcomfortable inside surface facing the patient. One suitable materialmight be, for example but without limitation, a laminated foam materialsuch as Breathoprene, which has a foam web faced on either side with aknitted fabric.

However, the collar can be more resistant to stretch than theBreathoprene material, and more breathable than the Breathoprenematerial. For comfort against the skin, the collar is preferably facedwith a woven, knitted or braided natural fibre fabric such as, forexample but without limitation, a braided or knitted tube of cotton orbamboo yarn. To provide form to the collar, the braided or knitted tubecan surround a flexible skeleton. The flexible skeleton might comprise aseries of hingedly connected frames, or a moulded flexible strap formedwith an open framework. Preferably, it comprises a narrow strap ofplastic mesh. An example of a suitable mesh is 3MESH, manufacture byMullter Texti Group of Germany. The open framework or mesh form allowsmoisture and heat to pass readily through the collar, reducingdiscomfort of the patient wearing the collar for long periods.

The collar strap is preferably about 3 cm to about 6 cm wide and betweenabout 3 mm and about 8 mm thick.

One preferred simple head strap is illustrated in FIGS. 3A to 3C. Itincludes a single, non-bifurcated strap terminated with a connector ateither end. The strap could be permanently connected to either end ofthe frame, but preferably the connectors are configured to be removablefrom the body of the mask. Another example of a preferred headstrap isillustrated in FIG. 10A to 10C, and a preferred connection clip isillustrated in FIGS. 63A to 63D.

The single non-bifurcated strap preferably accommodates a substantialvariation in head size without adjustment. The preferred strap has avery low stiffness with extension of a 400 mm king strap from a fullylaid out but unstretched condition to a condition about 1.3 times itsoriginal length after applying a force not exceeding about 4 N, andpreferably not exceeding about 2 N. FIG. 62 is a graph illustrating theforce versus extension characteristics of four sample strap materials.The preferred material comprises a knitted or braided tube nylon yarnincorporating strands of Lycra. The nylon yarn is sufficiently looselyformed that it is capable of extension beyond the range required withoutbecoming tight. The amount of Lycra strands in the yarn may be varied tovary the stiffness of the strap. An overall diameter or width of thestrap is preferably less than about 10 mm and most preferably less thanabout 6 mm.

The end connectors of the strap may be fixed to the strap in anysuitable manner. Preferably the end connectors are overmoulded to endsof the straps. Test results for a range of alternative strap materialsare illustrated in FIG. 62. All test results are for extensions of alength of the tested material from an “at rest” length of about 400 mm.

Line 6202 shows extension test results for a knitted yarn of nylonincorporating Lycra filaments, the knitted tube having a nominaldiameter of 5 mm. This also is stiffer than desirable.

Line 6206 illustrates a hypothetical most desirable response determinedby the inventors.

Line 6209 illustrates the response for an extended silicone hollow tubewith a wall thickness of about 0.25 mm and an outside diameter of about3 mm.

Line 6207 illustrates the response for an extended silicone hollow tubewith a wall thickness of about 0.25 mm and an outside diameter of about6 mm.

Both of these silicone extensions show satisfactory characteristics.

Line 6205 illustrates the response of the preferred knitted nylon yarnincorporating Lycra filaments. This knitted tube had a nominal diameterof about 4 mm.

Line 6208 illustrates the response of a length of about 3 mm wovenelastic webbing. This product exhibited similar characteristics to thepreferred knitted yarn, however the elastic webbing has a tendency tocatch hair and to lose elasticity.

The most preferred headstrap comprises a braided stretchable band.Lengths of stretchable thread are wound onto a plurality of spools. Thespools of the thread are then used in a braiding machine to produce acontinuous braided tube. The tube is passed over a roller or a pluralityof rollers, or between rollers, to flatten the tube into a band.

The preferred headstrap has a cross-sectional dimension of about 6 mmwide and about 1.5 mm thick.

According to the most preferred embodiment, the thread comprises a Lycra(elastane or sprandex) strand with a spun wrapper. The elastane strandmay be, for example, about 900 denier strand Lycra (elastane orspandex).

The spun wrapper may comprise at least one yarn of nylon filaments. Thewrapper may comprise a primary wrapper yarn and a secondary wrapperyarn. Each yarn may comprise a spun yarn comprising a plurality of nylonfilaments.

For example, each wrapper may comprise a yarn of nylon filaments.

The nylon filaments contribute the colour to the stretchable thread. Forexample, for a white headstrap, the nylon wrapper should comprise whitenylon filaments.

In preparing a spool of the stretchy thread, preferably multiple threads(preferably three threads) of stretchy thread are wound onto the spoolin parallel, so that each element in the braiding process actuallycomprises a bundle of three parallel threads.

Preferably, the braiding is conducted on a 16 spool braiding machine,such as a Ratera 16/80 braiding machine available from Talleres RateraSA of Barcelona, Spain. Each spool of thread for the braiding isprepared with three parallel threads, as described above.

The braiding machine is configured (for example by setting tensions,speeds or both) to produce a suitable braid. Example settings for theRatera 16 braiding machine speed control are A: 45, B: 20, C: 30 and D:35.

A headstrap produced in accordance with this description was tested bygradual extension, with the force at each extension recorded. The forceversus extension results for a 300 mm length of the prototype strapmaterial are shown in FIG. 64.

FIGS. 63A to 63C illustrate features of a preferred headgear strap. Inparticular they illustrate preferred arrangements for attaching aconnector to an end of a suitable stretchy strap material. They alsoillustrate a preferred connector for connecting the strap to the frameof the interface.

FIGS. 63D to 63I illustrate another similar headgear strap which sharesmany of the features of the headgear strap of FIGS. 63A to 63C. Exceptwhere noted, the following description refers to both embodiments andreference numerals are shared.

At least one end of the strap 6304 is terminated, and preferably bothends are terminated, with a connector 6302. Once the complete interfaceis assembled, the connectors 6302 engage the side portions 1016 of theframe.

To form the connector, the flattened tube 6306 is encapsulated by aplastic body 6308 or 6350, for example but without limitation, byovermoulding.

In the embodiment of FIGS. 63D to 63J, the band is encapsulated by acomparatively soft material such as a thermoplastic elastomer.

The plastic body 6308 may have gripping features on its outer surfaces,such as bumps or ridges 6324 or recesses 6352.

The body 6308 terminates at its other end in an end face which ispreferably sized and shaped to match the end face of side portions 1016.The connector and socket are preferably formed to provide a rigidconnection between the connector and the frame such that, when engaged,the connector is a rigid extension of the side portion of the frame.According to this, the connectors contribute their length to the frameto define the location at which the soft straps depart the frame.

The preferred connection comprises a metal plug portion extending fromthe end face of the connector 6302 to engage in socket 1062 formed inthe end face of the frame. The metal (preferably steel or titanium orsimilar material) plug portion has high stiffness and strength whileretaining a compact form.

The plug portion may advantageously be formed from a metal wire 6310.For example the plug portion may be formed from a length of stainlesssteel wire.

The wire may be bent back upon itself and have both ends enclosed by theconnector 6302, the wire thus forming a loop protruding from the endface of the connector. To cooperate with this loop the socket may be inthe form of a slot with an overall shape to match the essentially flatprong formed by the loop.

The loop may include a limb 6316 including a protruding kink or hump.The protruding kink 6322 is adapted to engage in a shallow notch 6344 inthe socket 1062. The notch 6344 may be formed along one edge surface ofthe slot.

The loop may be provided with a protruding end portion 6318 furthermostfrom the connector 6302. The slot may be provided with edge surfacesthat closely match at least the lateral profile of the end portion 6318so as to closely house the end portion with the loop engaged in theslot. This secures the connector against rotation in the plane of theloop.

The thickness of the slot preferably closely matches the thickness ofthe wire. This secures the connector against rotation transverse to theplane of the loop.

The loop may have a straight limb 6320, and the slot a complimentarystraight edge face. These straight faces provide a sliding referencesurface to align the connector with the socket during and afterengagement.

Where one of the limbs of the wire loop is kinked and the otherstraight, and complimentary surfaces are provided in the slot, theconnectors may be formed to have shapes which ensure correct orientationof the connectors relative to the socket. For example the connectors mayhave a form that is an apparent continuation of the form of the frame.

Where a connector and socket are provided at both ends of the strap, theconnectors (and the sockets) may have reversed orientation. For example,one socket may have depression 6334 at the lower edge face and the othersocket may have the depression at the upper edge face.

Alternatively the connectors may have a form or indication that ensurescorrect selection of the intended socket, as well as orientationrelative to the selected socket.

As seen in FIGS. 63A and 63C, one of the main limbs of the wire loop maybe free to move inside a cavity 6314 of the connector body 6308.Preferably, the free end 6340 is the end of the limb 6316 having theprotruding kink. The small freedom to move within cavity 6314 allows thewire loop to deflect more than if the end were constrained. Thisdeflection reduces the peak forces required (and generated in thesocket) during connection and disconnection of the connector.

The cavity 6314 comprises a slot opening into the connector body 6308from the end face of the connector body.

The other end of the wire loop may be formed to have a portion that iskeyed into the material of the connector body. For example, a portion ofthe wire may be bent into a curve and overmoulded with plastic materialof the connector body. This portion may overlap inside the connectorbody with the encapsulated end of the strap 6304.

For forming this connector, the wire loop and the strap may be assembledwith a sleeve, and the assembly may be overmoulded. For example, thesleeve (which may be plastic), may have a blind cavity that receives theend 6340 of the wire loop, and an open ended cavity that receives theother end of the wire loop (through one end of the cavity) and the endof the strap (through the other end of the cavity). The sleeve may thenbe overmoulded, or at least the open ended cavity holding the strap andintended fixed end of the loop may be filled. Alternatively, the sleevemay be formed in two halves, clipped together over the wire loop. Thetwo halves may, for example, be hinged together. The halves may alsoclip together over the end of the band 6306 and may roughly grip the endof the band before overmoulding. For example, gripping protrusions 6360may engage the end 6362 of the band.

According to the embodiment of FIGS. 63D to 63J, the soft cover material6350 is provided by overmoulding the connector with a soft material suchas a thermoplastic elastomer along a length of the very flexible floppyband 6306 beyond the sleeve. This leads to a flexible portion 6370transitioning between a rigid portion 6372 of the connector and the verysupple strap. Preferably, this flexible portion is progressively moreflexible moving away from the rigid portion 6372. For example, theovermoulded cover portion may taper extending away from the sleeve andindents may be provided in the cover (such as depressions 6352) or both.

On masks where the headgear strap will connect in a rigidly protrudingfashion (such as in some of the embodiments of the masks describedherein), the extending soft portion of the connector provides a softbuffer against impact from the protruding hard portion or prong.

Preferably, the soft portion extends from about 5 mm to about 60 mmalong the band or strap, most preferably from about 10 mm to about 20mm. The soft material may be chosen from a wide range of soft plasticswith consideration given to bonding with the strap material and thesleeve material.

With this connector, one of the edge surfaces of the socket 1062 mayinclude a first portion 6332 that matches the end portion 6318 of theloop, a depression or notch 6334 that matches the protruding kink 6322,a bump 6366 which secures the kink 6322 in the notch 6334, and arecessed lead in region 6338, which allows the loop to pass well intothe slot before the largest connection force is used to push the kink6322 past the bump 6366.

The described connector is compact, acts as an extension of the frame ofthe interface, and has a simple and intuitive method of connection anddisconnection.

FIGS. 58 to 61 illustrate another patient interface incorporating a sealsubstantially as described earlier, and like FIGS. 10 to 12 includesfeatures that may eliminate or reduce the need for additional support tothe conduit. According to this embodiment, the body of the mask includesdepending stabilizers 6102. A depending stabilizer is provided at eachside of the mask body. Each depending stabilizer extends beyond theperimeter of the mask seal and includes a foot 6104 to engage against,above or in the vicinity of the upper lip of the wearer. Preferably, thestabilizer does not extend beyond the inside surface of the seal, but isspaced forward from the inside surface of the seal, with the feet 6104located in a position such that with the mask donned and in usesymmetrically on the patient, the feet 6104 of the depending stabilizersdo not contact the wearer. Each foot 6104 may include a pad 6106 of softmaterial such as a soft polymer or elastomer foam or a section of hollowsilicone extrusion, for example but without limitation. The stabilizersmay be integrated with the seal rather than the frame, for example butwithout limitation, being integrally formed as a moulded silicone bodyextending from adjacent the central opening to protrude beyond the loweredge of the seal. In this case, features on the mask body could securethe position of the inboard ends of the stabilisers.

Each stabilizer extends in a downward direction to a region below theseal, and is intended to engage in the area of the upper lip of thepatient in the area bounded by the mouth, the nose and the nasolabialfolds and, preferably, not against the cheeks of the patient.Accordingly, the feet are profiled and positioned to fit within thisarea. Each stabilizer 6102 and arm 6108 extends from the lateral centralportion 6110 of the illustrated mask body. The form of this arm, and thematerial of this arm may be such that the arm is rigid, or that the armhas a desired degree of flexibility. Generally, this arm should besomewhat rigid.

The purpose of the stabilizers is to reside closely spaced from theupper lip portion of the user when the interface is correctly placed andto contact the upper lip region of the user when the interface is rockedto one side or the other relative to the user's nose, for example, underthe influence of the supply conduit. Gentle pressure on the foot 6104 ofthe stabilizer, which is laterally spaced from the centre line of themask, preferably toward the extreme edges of the mask, supports the maskagainst these side forces from the conduit, stopping the mask rockingtoo far across the face and breaking the seal.

Furthermore, the stabilizers depend below the mask and support the maskif the weight of the conduit tends to rotate mask forward. In that case,the feet 6104 of both stabilizers will contact the user's upper lip andsupport the position of the mask.

The stabilizers are illustrated in preferred form as having asubstantially rigid construction, but with flexible or soft pads 6106.However, to account for variations in patient geometry, thesestabilizers could be a selectable appendage with a connectionarrangement to the mask allowing replacement with stabilizers of adifferent form. Alternatively the stabilizers could be made to beadjusted, such as by providing hinge portions capable of multiple fixedpositions along the length of the stabiliser, or at the junction of thearms and feet or both. Alternatively, the arms could be formed of amalleable material which is capable of substantial yield. According tothis, the arms could be flexed into a desired position by yielding ofthe material and stay in that position. The soft pad of the stabilizercould be overmoulded onto portions of the frame. The frame and thestabilizers may be formed to have no sharp edges.

In the embodiment with hinging of the arms or feet, a linkagearrangement could be provided to link the movement of each of thestabilizers, or the stabilizers may be individually or collectivelysupported in position by a spring or springs or other resilient member.

With the addition of the stabilizers, the mask may be sufficientlysecure and placed on the patient without any desire for additionalsupport of the conduit. This in turn may allow a shorter length offlexible coupling tube 6120. Accordingly, the flexible coupling tube6210 (which would typically be much more flexible than the main supplyconduit) can be reduced in length to between about 5 cm and about 15 cm,and preferably about 10 cm. In systems that include a humidified gasessupply and a heated main supply conduit, this short flexible couplingtube is usually unheated. Where the coupling tube needs to be supportedby a lanyard or collar, there is a minimum length generally exceedingabout 15 cm. If the requirement for the lanyard and collar iseliminated, the shorter coupling tube is only provided for flexibility,to de-couple the relatively rigid supply conduit from the mask andfacilitate freedom of movement of the wearer's head. As the couplingtube is typically unheated, the humidity of the gases carried in thetube can rainout on the cooler wall surface creating collections ofwater which can ultimately be blown into the user's nostrils creatingdiscomfort. Providing a shorter tube, as allowed by the lip stabilisers,reduces the likelihood of rainout in the conduit.

The interface configuration incorporating a single supple headstrap, anasal seal, a low profile frame which can stabilise on the upper lip,all in a one size fits all package (preferably both the headstap and theseal) can be enhanced where the short coupling tube is especiallysupple. As used herein, the tube being supple means that it bends easilyunder applied forces. For example, suitable tubes may meet the testcriteria explained below with reference to FIG. 65.

According to the test of FIG. 65, a 150 mm length of tube is clamped ateach end to a cylindrical support at each end extending into the bore ofthe tube. This leaves approximately 130 mm of the tube suspended orbridging freely between the supported ends. This bridging portion shouldbe in a relaxed state, neither contracted or extended. A lateral forceof 5 N at the centre of the tube should lead to a deflection greaterthan 13 mm.

A number of examples of patient interface aspects of the interfaces, andvariations on each aspect, have been discussed with reference to otherFigures. The present application contemplates that an interface mayincorporate some aspects but not other aspects. For example, aninterface might incorporate aspects of the mask while using a differentarrangement for securing the mask to the user. An interface mightinclude a different mask while using inventive aspects of the strap tosecure that mask to the user. An interface may incorporate aspects ofthe mask but not make use of a similar, or any, structure for supportingthe weight of the conduit from the body of the patient. All of thesevariations are considered within the scope of this application.

Although the present invention has been described in terms of a certainembodiment, other embodiments apparent to those of ordinary skill in theart also are within the scope of this invention. Thus, various changesand modifications may be made without departing from the spirit andscope of the invention. For instance, various components may berepositioned as desired. Moreover, not all of the features, aspects andadvantages are necessarily required to practice the present invention.Accordingly, the scope of the present invention is intended to bedefined only by the claims that follow.

What is claimed is:
 1. A patient interface comprising: a mask assemblycomprising a seal and a frame; the seal comprising a pair of protrudingnostril locators, each nasal locator including an outlet apertureconfigured to seal against at least a nostril of a user, the seal alsocomprising an oval air supply aperture with a larger dimension of theoval air supply aperture extending in a lateral direction, and a rigidloop member extending around the air supply aperture and at least firstand second rigid barbs protruding from the rigid loop member atlocations adjacent to the oval air supply aperture; the frame comprisinga distal side comprising a connector connected to a flexible tube, theflexible tube comprising a supply connector located at a distal end ofthe flexible tube, the supply connector comprising a swivel, the framefurther comprising first and second lateral sides and first and secondarms extending from the first and second lateral sides, respectively,the frame also comprising first and second recesses clipped intoengagement with the first and second rigid barbs holding the seal intosealing engagement with a proximal side of the frame; a headstrapcomprising a knitted tubular material, a first headstrap end portion anda second headstrap end portion, the first and second headstrap endportions being removably engageable with the first and second arms; anoval arrangement of a plurality of bias flow holes disposed on thedistal side of the frame, the gas inlet disposed in a center of the ovalarrangement of the plurality of bias flow holes.
 2. A patient interfaceas claimed in claim 1, wherein the headstrap comprises a flattened tubeof the knitted tubular material and comprises first and second flattenedelongated side walls with a hollow area disposed between the first andsecond side walls, the first side wall having an outer surface facingtoward a user in use and the second side wall having an outer surfacefacing away from a user in use.
 3. A patient interface as claimed inclaim 1, wherein the first and second lateral arms comprise a connectionpoint for attachment of the first and second headstrap end portions, theconnection point comprising an elongate slot formed between proximal anddistal surfaces of the first and second lateral arms, at least portionsof the first and second headstrap end portions being received in arespective elongate slot.
 4. A patient interface comprising: a maskassembly comprising a seal and a frame; the seal comprising a pair ofprotruding nostril locators protruding from the seal, each nasal locatorincluding an outlet aperture configured to seal against at least anostril of the user, the seal also including an air supply aperture; theframe comprising a distal side comprising a connector connected to aflexible supply tube and a gas outlet clipped to the seal; a headstrapcomprising a knitted, hollow elongated tubular material with a first endand a second end, the first and second ends connected to the frame; anda plurality of bias flow holes disposed in an oval area on the distalside of the frame with a larger dimension of the oval area extending ina lateral direction, the connector disposed in a center of the ovalarea.
 5. A patient interface as claimed in claim 4, the seal comprisinga rigid loop member overmolded to the air supply aperture of the seal.6. A patient interface as claimed in claim 4, wherein the air supplyaperture is oval with a larger dimension of the air supply apertureextending in a lateral direction.
 7. A patient interface as claimed inclaim 5 additionally comprising at least one barbed member extendingfrom the rigid loop member into engagement with the frame.
 8. A patientinterface as claimed in claim 6, wherein the frame comprises at leastone recess clipped into engagement with the at least one barbed member.9. A patient interface as claimed in claim 4, wherein the seal alsocomprises first and second rigid barbs protruding from locationsadjacent to the air supply aperture.
 10. A patient interface as claimedin claim 8, wherein the first and second rigid barbs are on oppositesides of the air supply aperture.
 11. A patient interface as claimed inclaim 9, wherein the frame comprises first and second recesses clippedinto engagement with the first and second rigid barbs holding the sealinto sealing engagement with the frame.
 12. A patient interface asclaimed in claim 4, wherein the frame comprises first and second lateralsides and first and second arms extending from the first and secondlateral sides, respectively, the first and second arms connected to thefirst and second end portions of the headgear strap.
 13. A patientinterface as claimed in claim 12, wherein the first and second headstrapend portions are removably connectable with the first and second arms,the headstrap having a middle portion disposed adjacent a back of auser's head in use.
 14. A patient interface as claimed in claim 4,wherein the headstrap further comprises a first end portion and a secondend portion, the first and second end portions connected to the framematerial is hollow and elongated and comprises first and secondflattened elongated side walls with a hollow area disposed between thefirst and second side walls, the first side wall having an outer surfacefacing toward a user in use and the second side wall having an outersurface facing away from a user in use.
 15. A patient interfacecomprising: a mask assembly comprising a seal and a frame; the sealcomprising a pair of protruding nostril locators, each nasal locatorincluding an outlet aperture configured to seal against at least anostril of the user, the seal also including an air supply aperture andat least one rigid barb; the frame comprising a distal side comprisinggas inlet for connection with a gas supply conduit and a gas outletclipped to the at least a first rigid barb; and a headstrap comprising aknitted, tubular material connected to the frame.
 16. A patientinterface as claimed in claim 14 additionally comprising a connector forconnecting a gas supply conduit to the frame, the connector comprisingan overmolded connector.
 17. A patient interface as claimed in claim 14additionally comprising an oval arrangement of a plurality of bias flowholes disposed on the distal side of the frame, the gas inlet disposedin a center of the oval arrangement of the plurality of bias flow holes.18. A patient interface as claimed in claim 14 additionally comprisingat least a second rigid barb disposed on a side of the air supplyaperture opposite from the first rigid barb.
 19. A patient interface asclaimed in claim 14 additionally comprising a rigid loop memberovermolded to the air supply aperture, the at least one rigid barbextending from the rigid loop member.
 20. A patient interface as claimedin claim 18, additionally comprising at least second rigid barb memberextending from the rigid loop member.